Apple From Wikipedia, the free encyclopedia This article is about the fruit. For other uses, see Apple (disambiguation). Apple A typical apple Scientific classification Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Rosales Family: Rosaceae Subfamily: Maloideae or Spiraeoideae [1] Tribe: Maleae Genus: Malus Species: M. domestica Binomial name Malus domestica Borkh. The apple is the pomaceous fruit of the apple tree, species Malus domestica in the rose family (Rosaceae), and is a perennial. It is one of the most widely cultivated tree fruits, and the most widely known of the many members of genus Malus that are used by humans. The tree originated in Western Asia, where its wild ancestor is still found today. There are more than 7,500 known cultivars of apples, resulting in a range of desired characteristics. Cultivars vary in their yield and the ultimate size of the tree, even when grown on the same rootstock.[2] At least 55 million tonnes of apples were grown worldwide in 2005, with a value of about $10 billion. China produced about 35% of this total.[3] The United States is the second-leading producer, with more than 7.5% of world production. Iran is third, followed by Turkey, Russia, Italy and India. Contents [hide] 1 Botanical information 1.1 Wild ancestors 1.2 Genome 2 History 3 Cultural aspects 3.1 Germanic paganism 3.2 Greek mythology 3.3 The Apple in the Garden of Eden 4 Apple cultivars 5 Apple production 5.1 Apple breeding 5.2 Apple rootstocks 5.3 Pollination 5.4 Maturation and harvest 5.5 Storage 5.6 Pests and diseases 5.7 Records 6 Commerce 7 Human consumption 7.1 Fallen apples 7.2 Apple allergy 7.2.1 Symptoms 8 Health benefits 9 References 10 External links Botanical information Blossoms, fruits, and leaves of the apple tree (Malus domestica) Wild Malus sieversii apple in Kazakhstan The apple forms a tree that is small and deciduous, reaching 3 to 12 metres (9.8 to 39 ft) tall, with a broad, often densely twiggy crown.[4] The leaves are alternately arranged simple ovals 5 to 12 cm long and 3–6 centimetres (1.2–2.4 in) broad on a 2 to 5 centimetres (0.79 to 2.0 in) petiole with an acute tip, serrated margin and a slightly downy underside. Blossoms are produced in spring simultaneously with the budding of the leaves. The flowers are white with a pink tinge that gradually fades, five petaled, and 2.5 to 3.5 centimetres (0.98 to 1.4 in) in diameter. The fruit matures in autumn, and is typically 5 to 9 centimetres (2.0 to 3.5 in) in diameter. The center of the fruit contains five carpels arranged in a five-point star, each carpel containing one to three seeds.[4] Wild ancestors Main article: Malus sieversii The wild ancestors of Malus domestica are Malus sieversii, found growing wild in the mountains of Central Asia in southern Kazakhstan, Kyrgyzstan, Tajikistan, and Xinjiang, China,[5] and possibly also Malus sylvestris.[6] See also: Fruit tree propagation Genome In 2010, an Italian-led consortium announced they had decoded the complete genome of the apple (Golden delicious variety).[7] It had about 57,000 genes, the highest number of any plant genome studied to date and more genes than the human genome (about 30,000).[8] History See also: Herefordshire Pomona The center of diversity of the genus Malus is in eastern Turkey. The apple tree was perhaps the earliest tree to be cultivated,[9] and its fruits have been improved through selection over thousands of years. Alexander the Great is credited with finding dwarfed apples in Asia Minor in 300 BCE;[4] those he brought back to Macedonia might have been the progenitors of dwarfing root stocks. Winter apples, picked in late autumn and stored just above freezing, have been an important food in Asia and Europe for millennia, as well as in Argentina and in the United States since the arrival of Europeans.[9] Apples were brought to North America with colonists in the 17th century,[4] and the first apple orchard on the North American continent was said to be near Boston in 1625. In the 20th century, irrigation projects in Washington state began and allowed the development of the multibillion dollar fruit industry, of which the apple is the leading species.[4] Until the 20th century, farmers stored apples in frostproof cellars during the winter for their own use or for sale. Improved transportation of fresh apples by train and road replaced the necessity for storage.[10][11] Cultural aspects Main article: Apple (symbolism) "Brita as Iduna" (1901) by Carl Larsson Germanic paganism In Norse mythology, the goddess Iðunn is portrayed in the Prose Edda (written in the 13th century by Snorri Sturluson) as providing apples to the gods that give them eternal youthfulness. English scholar H. R. Ellis Davidson links apples to religious practices in Germanic paganism, from which Norse paganism developed. She points out that buckets of apples were found in the Oseberg ship burial site in Norway, and that fruit and nuts (Iðunn having been described as being transformed into a nut in Skáldskaparmál) have been found in the early graves of the Germanic peoples in England and elsewhere on the continent of Europe, which may have had a symbolic meaning, and that nuts are still a recognized symbol of fertility in southwest England.[12] Davidson notes a connection between apples and the Vanir, a tribe of gods associated with fertility in Norse mythology, citing an instance of eleven "golden apples" being given to woo the beautiful Gerðr by Skírnir, who was acting as messenger for the major Vanir god Freyr in stanzas 19 and 20 of Skírnismál. Davidson also notes a further connection between fertility and apples in Norse mythology in chapter 2 of the Völsunga saga when the major goddess Frigg sends King Rerir an apple after he prays to Odin for a child, Frigg's messenger (in the guise of a crow) drops the apple in his lap as he sits atop a mound.[13] Rerir's wife's consumption of the apple results in a six-year pregnancy and the Caesarean section birth of their son - the hero Völsung.[14] Further, Davidson points out the "strange" phrase "Apples of Hel" used in an 11th-century poem by the skald Thorbiorn Brúnarson. She states this may imply that the apple was thought of by the skald as the food of the dead. Further, Davidson notes that the potentially Germanic goddess Nehalennia is sometimes depicted with apples and that parallels exist in early Irish stories. Davidson asserts that while cultivation of the apple in Northern Europe extends back to at least the time of the Roman Empire and came to Europe from the Near East, the native varieties of apple trees growing in Northern Europe are small and bitter. Davidson concludes that in the figure of Iðunn "we must have a dim reflection of an old symbol: that of the guardian goddess of the life-giving fruit of the other world."[12] Greek mythology Heracles with the apple of Hesperides Apples appear in many religious traditions, often as a mystical or forbidden fruit. One of the problems identifying apples in religion, mythology and folktales is that the word "apple" was used as a generic term for all (foreign) fruit, other than berries, but including nuts, as late as the 17th century.[15] For instance, in Greek mythology, the Greek hero Heracles, as a part of his Twelve Labours, was required to travel to the Garden of the Hesperides and pick the golden apples off the Tree of Life growing at its center.[16][17][18] The Greek goddess of discord, Eris, became disgruntled after she was excluded from the wedding of Peleus and Thetis.[19] In retaliation, she tossed a golden apple inscribed Καλλίστη (Kalliste, sometimes transliterated Kallisti, 'For the most beautiful one'), into the wedding party. Three goddesses claimed the apple: Hera, Athena, and Aphrodite. Paris of Troy was appointed to select the recipient. After being bribed by both Hera and Athena, Aphrodite tempted him with the most beautiful woman in the world, Helen of Sparta. He awarded the apple to Aphrodite, thus indirectly causing the Trojan War. The apple was thus considered, in ancient Greece, to be sacred to Aphrodite, and to throw an apple at someone was to symbolically declare one's love; and similarly, to catch it was to symbolically show one's acceptance of that love.[20] An epigram claiming authorship by Plato states: I throw the apple at you, and if you are willing to love me, take it and share your girlhood with me; but if your thoughts are what I pray they are not, even then take it, and consider how short-lived is beauty. —Plato, Epigram VII[21] Adam and Eve Showcasing the apple as a symbol of sin. Albrecht Dürer, 1507 Atalanta, also of Greek mythology, raced all her suitors in an attempt to avoid marriage. She outran all but Hippomenes (a.k.a. Melanion, a name possibly derived from melon the Greek word for both "apple" and fruit in general),[17] who defeated her by cunning, not speed. Hippomenes knew that he could not win in a fair race, so he used three golden apples (gifts of Aphrodite, the goddess of love) to distract Atalanta. It took all three apples and all of his speed, but Hippomenes was finally successful, winning the race and Atalanta's hand.[16] The Apple in the Garden of Eden Though the forbidden fruit in the Book of Genesis is not identified, popular Christian tradition has held that it was an apple that Eve coaxed Adam to share with her.[22] This may have been the result of Renaissance painters adding elements of Greek mythology into biblical scenes (alternative interpretations also based on Greek mythology occasionally replace the apple with a pomegranate). In this case the unnamed fruit of Eden became an apple under the influence of story of the golden apples in the Garden of Hesperides. As a result, in the story of Adam and Eve, the apple became a symbol for knowledge, immortality, temptation, the fall of man into sin, and sin itself. In Latin, the words for "apple" and for "evil" are similar (mālum "an apple", mălum "an evil, a misfortune"). This may also have influenced the apple becoming interpreted as the biblical "forbidden fruit". The larynx in the human throat has been called Adam's apple because of a notion that it was caused by the forbidden fruit sticking in the throat of Adam.[22] The apple as symbol of sexual seduction has been used to imply sexuality between men, possibly in an ironic vein.[22] Apple cultivars Main article: List of apple cultivars Different kinds of apple cultivars in a supermarket 'Sundown' apple cultivar and its cross section There are more than 7,500 known cultivars of apples.[23] Different cultivars are available for temperate and subtropical climates. One large collection of over 2,100[24] apple cultivars is housed at the National Fruit Collection in England. Most of these cultivars are bred for eating fresh (dessert apples), though some are cultivated specifically for cooking (cooking apples) or producing cider. Cider apples are typically too tart and astringent to eat fresh, but they give the beverage a rich flavour that dessert apples cannot.[25] Commercially popular apple cultivars are soft but crisp. Other desired qualities in modern commercial apple breeding are a colourful skin, absence of russeting, ease of shipping, lengthy storage ability, high yields, disease resistance, typical 'Red Delicious' apple shape, and popular flavour.[2] Modern apples are generally sweeter than older cultivars, as popular tastes in apples have varied over time. Most North Americans and Europeans favour sweet, subacid apples, but tart apples have a strong minority following.[26] Extremely sweet apples with barely any acid flavour are popular in Asia[26] and especially India.[25] Old cultivars are often oddly shaped, russeted, and have a variety of textures and colours. Some find them to have a better flavour than modern cultivators,[27] but may have other problems which make them commercially unviable, such as low yield, liability to disease, or poor tolerance for storage or transport. A few old cultivars are still produced on a large scale, but many have been kept alive by home gardeners and farmers that sell directly to local markets. Many unusual and locally important cultivars with their own unique taste and appearance exist; apple conservation campaigns have sprung up around the world to preserve such local cultivars from extinction. In the United Kingdom, old cultivars such as 'Cox's Orange Pippin' and 'Egremont Russet' are still commercially important even though by modern standards they are low yielding and disease prone.[4] Apple production Apple breeding Apple blossom from an old Ayrshire variety In the wild, apples grow quite readily from seeds. However, like most perennial fruits, apples are ordinarily propagated asexually by grafting. This is because seedling apples are an example of "extreme heterozygotes", in that rather than inheriting DNA from their parents to create a new apple with those characteristics, they are instead different from their parents, sometimes radically.[28] Triploids have an additional reproductive barrier in that the 3 sets of chromosomes cannot be divided evenly during meiosis, yielding unequal segregation of the chromosomes (aneuploids). Even in the very unusual case when a triploid plant can produce a seed (apples are an example), it happens infrequently, and seedlings rarely survive.[29] Most new apple cultivars originate as seedlings, which either arise by chance or are bred by deliberately crossing cultivars with promising characteristics.[30] The words 'seedling', 'pippin', and 'kernel' in the name of an apple cultivar suggest that it originated as a seedling. Apples can also form bud sports (mutations on a single branch). Some bud sports turn out to be improved strains of the parent cultivar. Some differ sufficiently from the parent tree to be considered new cultivars.[31] Breeders can produce more rigid apples through crossing.[32] For example, the Excelsior Experiment Station of the University of Minnesota has, since the 1930s, introduced a steady progression of important hardy apples that are widely grown, both commercially and by backyard orchardists, throughout Minnesota and Wisconsin. Its most important introductions have included 'Haralson' (which is the most widely cultivated apple in Minnesota), 'Wealthy', 'Honeygold', and 'Honeycrisp'. Apples have been acclimatized in Ecuador at very high altitudes, where they provide crops twice per year because of constant temperate conditions in a whole year.[33] Apple rootstocks See also: Malling series Rootstocks used to control tree size have been used in apple cultivation for over 2,000 years. Dwarfing rootstocks were probably discovered by chance in Asia. Alexander the Great sent samples of dwarf apple trees back to his teacher, Aristotle, in Greece. They were maintained at the Lyceum, a center of learning in Greece. Most modern apple rootstocks were bred in the 20th century. Much research into the existing rootstocks was begun at the East Malling Research Station in Kent, England. Following that research, Malling worked with the John Innes Institute and Long Ashton to produce a series of different rootstocks with disease resistance and a range of different sizes, which have been used all over the world. Pollination See also: Fruit tree pollination Apple tree in flower Orchard mason bee on apple bloom, British Columbia, Canada Apples are self-incompatible; they must cross-pollinate to develop fruit. During the flowering each season, apple growers usually provide pollinators to carry the pollen. Honeybees are most commonly used. Orchard mason bees are also used as supplemental pollinators in commercial orchards. Bumble bee queens are sometimes present in orchards, but not usually in enough quantity to be significant pollinators.[31] There are four to seven pollination groups in apples, depending on climate: Group A – Early flowering, May 1 to 3 in England (Gravenstein, Red Astrachan) Group B – May 4 to 7 (Idared, McIntosh) Group C – Mid-season flowering, May 8 to 11 (Granny Smith, Cox's Orange Pippin) Group D – Mid/late season flowering, May 12 to 15 (Golden Delicious, Calville blanc d'hiver) Group E – Late flowering, May 16 to 18 (Braeburn, Reinette d'Orléans) Group F – May 19 to 23 (Suntan) Group H – May 24 to 28 (Court-Pendu Gris) (also called Court-Pendu plat) One cultivar can be pollinated by a compatible cultivar from the same group or close (A with A, or A with B, but not A with C or D).[34] Varieties are sometimes classed as to the day of peak bloom in the average 30 day blossom period, with pollinizers selected from varieties within a 6 day overlap period. Maturation and harvest See also: Apple picking and Pruning fruit trees Cultivars vary in their yield and the ultimate size of the tree, even when grown on the same rootstock. Some cultivars, if left unpruned, will grow very large, which allows them to bear much more fruit, but makes harvesting very difficult. Mature trees typically bear 40–200 kilograms (88–440 lb) of apples each year, though productivity can be close to zero in poor years. Apples are harvested using three-point ladders that are designed to fit amongst the branches. Dwarf trees will bear about 10–80 kilograms (22–180 lb) of fruit per year.[31] Storage Commercially, apples can be stored for some months in controlled-atmosphere chambers to delay ethylene-induced onset of ripening. The apples are commonly stored in chambers with higher concentrations of carbon dioxide with high air filtration. This prevents ethylene concentrations from rising to higher amounts and preventing ripening from moving too quickly. Ripening continues when the fruit is removed.[35] For home storage, most varieties of apple can be held for approximately two weeks when kept at the coolest part of the refrigerator (i.e. below 5°C). Some types, including the Granny Smith and Fuji, have a longer shelf life.[36] Pests and diseases Leaves with significant insect damage Main article: List of apple diseases See also: List of Lepidoptera that feed on apple trees The trees are susceptible to a number of fungal and bacterial diseases and insect pests. Many commercial orchards pursue an aggressive program of chemical sprays to maintain high fruit quality, tree health, and high yields. A trend in orchard management is the use of organic methods. These use a less aggressive and direct methods of conventional farming. Instead of spraying potent chemicals, often shown to be potentially dangerous and maleficent to the tree in the long run, organic methods include encouraging or discouraging certain cycles and pests. To control a specific pest, organic growers might encourage the prosperity of its natural predator instead of outright killing it, and with it the natural biochemistry around the tree. Organic apples generally have the same or greater taste than conventionally grown apples, with reduced cosmetic appearances.[37] A wide range of pests and diseases can affect the plant; three of the more common diseases/pests are mildew, aphids and apple scab. Mildew: which is characterized by light grey powdery patches appearing on the leaves, shoots and flowers, normally in spring. The flowers will turn a creamy yellow colour and will not develop correctly. This can be treated in a manner not dissimilar from treating Botrytis; eliminating the conditions which caused the disease in the first place and burning the infected plants are among the recommended actions to take.[38][38] Feeding aphids Aphids: There are five species of aphids commonly found on apples: apple grain aphid, rosy apple aphid, apple aphid, spirea aphid and the woolly apple aphid. The aphid species can be identified by their colour, the time of year when they are present and by differences in the cornicles, which are small paired projections from the rear of aphids.[38] Aphids feed on foliage using needle-like mouth parts to suck out plant juices. When present in high numbers, certain species reduce tree growth and vigor.[39] Apple scab: Symptoms of scab are olive-green or brown blotches on the leaves.[40] The blotches turn more brown as time progresses, then brown scabs form on the fruit.[38] The diseased leaves will fall early and the fruit will become increasingly covered in scabs - eventually the fruit skin will crack. Although there are chemicals to treat scab, their use might not be encouraged as they are quite often systematic, which means they are absorbed by the tree, and spread throughout the fruit.[40] Among the most serious disease problems are fireblight, a bacterial disease; and Gymnosporangium rust, and black spot, two fungal diseases.[39] Young apple trees are also prone to mammal pests like mice and deer, which feed on the soft bark of the trees, especially in winter. Records Guinness World Records reports that the heaviest apple known weighed 1.849 kg (4 lb 1 oz) and was grown in Hirosaki city, Japan in 2005.[41] Commerce Worldwide apple production At least 55 million tonnes of apples were grown worldwide in 2005, with a value of about $10 billion. China produced about two-fifths of this total.[42] United States is the second leading producer, with more than 7.5% of the world production.[30] In the United States, more than 60% of all the apples sold commercially are grown in Washington state.[43] Imported apples from New Zealand and other more temperate areas are competing with US production and increasing each year.[42] Most of Australia's apple production is for domestic consumption. Imports from New Zealand have been disallowed under quarantine regulations for fireblight since 1921.[44] The largest exporters of apples in 2006 were China, Chile, Italy, France and the U.S., while the biggest importers in the same year were Russia, Germany, the UK and the Netherlands.[45] Top Ten Apple Producers — 11 June 2008 Country Production (Tonnes) Footnote People's Republic of China 27 507 000 F United States 4 237 730 Iran 2 660 000 F Turkey 2 266 437 Russia 2 211 000 F Italy 2 072 500 India 2 001 400 France 1 800 000 F Chile 1 390 000 F Argentina 1 300 000 F World 64 255 520 A No symbol = official figure, F = FAO estimate, A = Aggregate (may include official, semi-official, or estimates); Source: FAO Human consumption See also: Cooking apple and Cider apple Apples can be canned or juiced. They are milled to produce apple cider (non-alcoholic, sweet cider) and filtered for apple juice. The juice can be fermented to make cider (alcoholic, hard cider), ciderkin, and vinegar. Through distillation, various alcoholic beverages can be produced, such as applejack, Calvados,[46] and apple wine. Pectin and apple seed oil may also produced. Apples are an important ingredient in many desserts, such as apple pie, apple crumble, apple crisp and apple cake. They are often eaten baked or stewed, and they can also be dried and eaten or reconstituted (soaked in water, alcohol or some other liquid) for later use. Puréed apples are generally known as apple sauce. Apples are also made into apple butter and apple jelly. They are also used (cooked) in meat dishes. In the UK, a toffee apple is a traditional confection made by coating an apple in hot toffee and allowing it to cool. Similar treats in the US are candy apples (coated in a hard shell of crystallised sugar syrup), and caramel apples, coated with cooled caramel. Apples are eaten with honey at the Jewish New Year of Rosh Hashanah to symbolize a sweet new year.[46] Farms with apple orchards may open them to the public, so consumers may themselves pick the apples they will buy.[46] Sliced apples turn brown with exposure to air due to the conversion of natural phenolic substances into melanin upon exposure to oxygen.[47] Different cultivars vary in their propensity to brown after slicing. Sliced fruit can be treated with acidulated water to prevent this effect.[47] Organic apples are commonly produced in the United States.[48] Organic production is difficult in Europe, though a few orchards have done so with commercial success,[48] using disease-resistant cultivars and the very best cultural controls. The latest tool in the organic repertoire is a spray of a light coating of kaolin clay, which forms a physical barrier to some pests, and also helps prevent apple sun scald.[31][48] Fallen apples This section needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (March 2010) This section may contain original research. Please improve it by verifying the claims made and adding references. Statements consisting only of original research may be removed. More details may be available on the talk page. (March 2010) Eating fallen apples (known in the UK as 'windfalls'), rather than picking directly from the tree, is generally safe. There may be a risk of food poisoning if the orchard is also the area of keeping cattle or other animals, which may contaminate the apples with feces. Still, the risk may be significantly higher if the apples are used to make home-made (unpasteurized) cider or juice, thus letting E. coli multiply.[49] On the other hand, if the apples are eaten unprocessed, and kept free from risk of contamination with animal feces, then eating fallen apples is generally safe, even if there is some general decay or worms in them. Still, they may be submerged in water with salt added, which kills the worms.[50] Apparent molds may be largely removed by putting in water with some vinegar added,[50] but if they are of a large quantity, then there might be mold or mold products left to evoke mold health issues such as allergic reactions and respiratory problems. Apple allergy Oral allergy syndrome is an allergic reaction some people will experience due to the birch pollen left on the apples.[51][52] Because the pollen is the main irritant, only the raw apples, especially their skin, cause the allergic reaction. Cooked apples do not cause these symptoms as the heat denatures the proteins in the pollen, rendering them harmless to those sensitive. If one is allergic to apples, he or she may also experience an allergic reaction with other fruits in the Rosaceae family which include peaches and hazelnuts.[51] Symptoms Symptoms vary from person to person but are generally mild. This typically includes the sensation of itching and swelling around the mouth and lips. Other symptoms include watery eyes, runny nose and sneezing. Hives may develop in those who have a high sensitivity to the pollen. Abdominal pain and diarrhea may also occur.[51] Health benefits Apples, with skin (edible parts) Nutritional value per 100 g (3.5 oz) Energy 218 kJ (52 kcal) Carbohydrates 13.81 g Sugars 10.39 g Dietary fiber 2.4 g Fat 0.17 g Protein 0.26 g Water 85.56 g Vitamin A equiv. 3 μg (0%) Thiamine (Vit. B1) 0.017 mg (1%) Riboflavin (Vit. B2) 0.026 mg (2%) Niacin (Vit. B3) 0.091 mg (1%) Pantothenic acid (B5) 0.061 mg (1%) Vitamin B6 0.041 mg (3%) Folate (Vit. B9) 3 μg (1%) Vitamin C 4.6 mg (8%) Calcium 6 mg (1%) Iron 0.12 mg (1%) Magnesium 5 mg (1%) Phosphorus 11 mg (2%) Potassium 107 mg (2%) Zinc 0.04 mg (0%) Percentages are relative to US recommendations for adults. Source: USDA Nutrient database Health benefits of apple consumption.[53][54][55][56] The proverb "An apple a day keeps the doctor away.", addressing the health effects of the fruit, dates from the 19th century Wales.[57] Research suggests that apples may reduce the risk of colon cancer, prostate cancer and lung cancer.[53] Compared to many other fruits and vegetables, apples contain relatively low amounts of vitamin C, but are a rich source of other antioxidant compounds.[47] The fiber content, while less than in most other fruits, helps regulate bowel movements and may thus reduce the risk of colon cancer. They may also help with heart disease,[58] weight loss,[58] and controlling cholesterol,[58] as they do not have any cholesterol, have fiber, which reduces cholesterol by preventing reabsorption, and (like most fruits and vegetables) are bulky for their caloric content.[55][58] There is evidence that in vitro apples possess phenolic compounds which may be cancer-protective and demonstrate antioxidant activity.[59] The predominant phenolic phytochemicals in apples are quercetin, epicatechin, and procyanidin B2.[60] Apple juice concentrate has been found to increase the production of the neurotransmitter acetylcholine in mice, providing a potential mechanism for the "prevention of the decline in cognitive performance that accompanies dietary and genetic deficiencies and aging." Other studies have shown an "alleviat[ion of] oxidative damage and cognitive decline" in mice after the administration of apple juice.[56] However, apple seeds are mildly poisonous, containing a small amount of amygdalin, a cyanogenic glycoside; it usually is not enough to be dangerous to humans, but can deter birds.[61] References ^ Potter, D.; Eriksson, T.; Evans, R.C.; Oh, S.H.; Smedmark, J.E.E.; Morgan, D.R.; Kerr, M.; Robertson, K.R.; Arsenault, M.P.; Dickinson, T.A.; Campbell, C.S. (2007). Phylogeny and classification of Rosaceae. Plant Systematics and Evolution. 266(1–2): 5–43. ^ a b "Apple - Malus domestica". Natural England. Retrieved 22 January 2008. ^ "Apple". Jinxiang High Garlics Co., Ltd. Retrieved 2008-08-18. ^ a b c d e f "Origin, History of cultivation". University of Georgia. Archived from the original on 21 January 2008. Retrieved 22 January 2008. ^ Lauri, Pierre-éric; Karen Maguylo, Catherine Trottier (2006). "Architecture and size relations: an essay on the apple (Malus x domestica, Rosaceae) tree". American Journal of Botany (Botanical Society of America, Inc.) (93): 357–368. ^ Coart, E., Van Glabeke, S., De Loose, M., Larsen, A.S., Roldán-Ruiz, I. 2006. Chloroplast diversity in the genus Malus: new insights into the relationship between the European wild apple (Malus sylvestris (L.) Mill.) and the domesticated apple (Malus domestica Borkh.). Mol. Ecol. 15(8): 2171-82. ^ An Italian-led international research consortium decodes the apple genome AlphaGallileo August 29, 2010. Retrieved August 29, 2010. ^ The Science Behind the Human Genome Project Human Genome Project Information, US Department of Energy, March 26, 2008. Retrieved September 24, 2010. ^ a b "An apple a day keeps the doctor away". vegparadise.com. Retrieved 27 January 2008. ^ James M. Van Valen (2010). History of Bergen county, New Jersey. Nabu Press. p. 744. ISBN 1177725894. 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Rochester: Park Street Press. pp. 64–70. ISBN 0-89281-997-9. ^ Herodotus Histories 6.1.191. ^ Edmonds, J. M., trans.; rev. John M. Cooper. "Epigrams". Plato: Complete Works. Ed. John M. Cooper. Indianapolis: Hackett, 1997. p 1744, note to VII. Print. ^ Edmonds, J. M., trans.; rev. John M. Cooper. "Epigrams". Plato: Complete Works. Ed. John M. Cooper. Indianapolis: Hackett, 1997. p 1744. Print. ^ a b c Macrone, Michael; Tom Lulevitch (1998). Brush up your Bible!. Tom Lulevitch. Random House Value. ISBN 0517201895. OCLC 38270894. ^ Elzebroek, A.T.G.; Wind, K. (2008). Guide to Cultivated Plants. Wallingford: CAB International. p. 27. ISBN 1845933567. ^ "National Fruit Collections at Brogdale", Farm Advisory Services Team. Retrieved 2009-10-27. ^ a b Sue Tarjan (fall 2006). "Autumn Apple Musings" (PDF). News & Notes of the UCSC Farm & Garden, Center for Agroecology & Sustainable Food Systems. pp. 1–2. Archived from the original on August 11, 2007. Retrieved 24 January 2008. ^ a b "World apple situation". Retrieved 24 January 2008. ^ Weaver, Sue (June/July 2003). "Crops & Gardening - Apples of Antiquity". Hobby Farms magazine (BowTie, Inc). ^ John Lloyd and John Mitchinson. (2006). QI: The Complete First Series - QI Factoids. [DVD]. 2 entertain. ^ "NCSU.edu". Ces.ncsu.edu. 2009-07-24. Retrieved 2010-11-07. ^ a b Ferree, David Curtis; Ian J. Warrington (1999). Apples: Botany, Production and Uses. CABI Publishing. ISBN 0851993575. OCLC 182530169. ^ a b c d Bob Polomski; Greg Reighard. "Apple". Clemson University. Retrieved 22 January 2008. ^ "Apples". solarnavigator.net. Retrieved 22 January 2008. ^ "Apples in Ecuador". Acta Hort. Retrieved 2008-07-17. ^ S. Sansavini (1 July 1986). "The chilling requirement in apple and its role in regulating Time of flowering in spring in cold-Winter Climate". Symposium on Growth Regulators in Fruit Production (International ed.). Acta Horticulturae. p. 179. ISBN 978-90-66051-82-9. ^ "Controlled Atmosphere Storage (CA)". Washington State Apple Advertising Commission. Retrieved 24 January 2008. ^ "Food Science Australia Fact Sheet: Refrigerated storage of perishable foods". Food Science Australia. February, 2005. Retrieved 2007-05-25. ^ Pittsburgh Section, University of Pittsburgh School of Engineering, School of Engineering, Institute of Electrical and Electronics Engineers Pittsburgh Section, Instrument Society of America, Instrument Society of America Pittsburgh Section, University of Pittsburgh (1981). Modeling and Simulation: Proceedings of the Annual Pittsburgh Conference. Instrument Society of America. ^ a b c d Lowther, Granville; William Worthington. The Encyclopedia of Practical Horticulture: A Reference System of Commercial Horticulture, Covering the Practical and Scientific Phases of Horticulture, with Special Reference to Fruits and Vegetables. The Encyclopedia of horticulture corporation. ^ a b Coli, William et al.. "Apple Pest Management Guide". University of Massachusetts Amherst. Retrieved 3 March 2008. ^ a b "How To Deal With Scab". GardenAction. Retrieved 3 March 2008. ^ "Plant World - Heaviest Apple". Guinness World Records. Retrieved 2009-09-09. ^ a b Kristin Churchill. "Chinese apple-juice concentrate exports to United States continue to rise". Great American Publishing. Archived from the original on October 16, 2006. Retrieved 22 January 2008. ^ Desmond, Andrew (1994). The World Apple Market. Haworth Press. pp. 144–149. ISBN 1560220414. OCLC 243470452. ^ Gavin Evans (Tuesday, August 9, 2005). "Fruit ban rankles New Zealand - Australian apple growers say risk of disease justifies barriers". International Herald Tribune. Retrieved 9 August 2005. ^ "FAO". Faostat.fao.org. 2009-08-12. Retrieved 2010-11-07. ^ a b c "Apples". Washington State Apple Advertising Commission. Retrieved 22 January 2008. ^ a b c Boyer, J; Liu, RH; Rui Hai Liu (May 2004). "Apple phytochemicals and their health benefits". Nutrition journal (Cornell University, Ithaca, New York 14853-7201 USA: Department of Food Science and Institute of Comparative and Environmental Toxicology) 3: 5. doi:10.1186/1475-2891-3-5. PMID 15140261. PMC 442131. ^ a b c Ames, Guy (July 2001). "Considerations in organic apple production" (PDF). National Sustainable Agriculture Information Service. Retrieved 24 January 2008. ^ Food Poisoning and Safety California Poison Control System ^ a b fallen apples – safe? iVillage Garden Web ^ a b c "Wrongdiagnosis.com". Wrongdiagnosis.com. 2010-10-31. Retrieved 2010-11-07. ^ "Webmd.com". Webmd.com. Retrieved 2010-11-07. ^ a b For decreased risk of colon, prostate and lung cancer: "Nutrition to Reduce Cancer Risk". The Stanford Cancer Center (SCC). Retrieved 2008-08-18. ^ For weight loss and cholesterol control: "Apples Keep Your Family Healthy". Washington State Apple Advertising Commission. Retrieved 22 January 2008. ^ a b Rajeev Sharma. (2005). Improve your health with Apple,Guava,Mango. Diamond Pocket Books (P) Ltd.. p. 22. ISBN 8128809245. ^ a b For prevention of dementia: Chan A, Graves V, Shea TB, A (Aug 2006). "Apple juice concentrate maintains acetylcholine levels following dietary compromise". Journal of Alzheimer's Disease 9 (3): 287–291. ISSN 1387-2877. PMID 16914839. ^ Phillips, John Pavin (1866-02-24). "A Pembrokeshire Proverb". Notes and Queries (Oxford University Press) s3-IX (217): 153. Retrieved 2009-02-11. ^ a b c d "Apples Keep Your Family Healthy". Washington State Apple Advertising Commission. Retrieved 22 January 2008. ^ Lee KW, Lee SJ, Kang NJ, Lee CY, Lee HJ, KW (2004). "Effects of phenolics in Empire apples on hydrogen peroxide-induced inhibition of gap-junctional intercellular communication". Biofactors 21 (1–4): 361–5. doi:10.1002/biof.552210169. ISSN 0951-6433. PMID 15630226. ^ Lee KW, Kim YJ, Kim DO, Lee HJ, Lee CY, KW (Oct 2003). "Major phenolics in apple and their contribution to the total antioxidant capacity". J. Agric. Food Chem. 51 (22): 6516–6520. doi:10.1021/jf034475w. ISSN 0021-8561. PMID 14558772. ^ Juniper BE, Mabberley DJ (2006). The Story of the Apple. Timber Press. p. 20. ISBN 0881927848. Pome From Wikipedia, the free encyclopedia An apple is a pome fruit. The parts of the fruit are labelled In botany, a pome (after the Latin word for fruit: pōmum) is a type of fruit produced by flowering plants in the subfamily Maloideae of the family Rosaceae. A pome is an accessory fruit composed of one or more carpels surrounded by accessory tissue. The accessory tissue is interpreted by some specialists as an extension of the receptacle and is then referred to as "fruit cortex",[1] and by others as a fused hypanthium[1] or "torus";[2] it is the most edible part of this fruit. Although the exocarp, mesocarp, and endocarp of some other fruit types look very much like the skin, flesh, and core respectively of a pome, they are parts of the carpel (see diagram). The exocarp and mesocarp of a pome may be fleshy and difficult to distinguish from one another and from the hypanthial tissue. The endocarp forms a leathery or stony case around the seed, and corresponds to what is commonly called the core. The shriveled remains of the sepals, style and stamens can sometimes be seen at the end of a pome opposite the stem, and the ovary is therefore often described as inferior in these flowers. [edit]Examples The best-known example of a pome is the apple. Other examples of plants that produce fruit classified as a pome are cotoneaster, hawthorn, loquat, medlar, pear, pyracantha, toyon, quince,[2] rowan, and whitebeam. Some pomes may have a mealy texture (e.g., some apples); others (e.g., Amelanchier) are berry-like with juicy flesh and a core that is not very noticeable. [edit]See also Nut (fruit) [edit]References ^ a b Esau, K. 1977. Anatomy of seed plants. John Wiley and Sons, New York. ^ a b Jonathan Pereira, Fred B. Kilmer, Joseph Carson, Alfred Swaine Taylor, George Owen Rees (1857) The Elements of Materia Medica and Therapeutics, Published by Longman, Brown, Green, and Longman's, v.2:pt.2 Fruit From Wikipedia, the free encyclopedia For other uses, see Fruit (disambiguation). Several culinary fruits Common culinary fruits. Fruit basket painted by Balthasar van der Ast The Medici citrus collection by Bartolomeo Bimbi, 1715 Fruit and vegetable output in 2004 In broad terms, a fruit is a structure of a plant that contains its seeds. The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state, such as apples, oranges, grapes, strawberries, juniper berries and bananas. Seed-associated structures that do not fit these informal criteria are usually called by other names, such as vegetables, pods, nut, ears and cones. In biology (botany), a "fruit" is a part of a flowering plant that derives from specific tissues of the flower, mainly one or more ovaries. Taken strictly, this definition excludes many structures that are "fruits" in the common sense of the term, such as those produced by non-flowering plants (like juniper berries, which are the seed-containing female cones of conifers[1]), and fleshy fruit-like growths that develop from other plant tissues close to the fruit (accessory fruit, or more rarely false fruit or pseudocarp), such as cashew fruits. Often the botanical fruit is only part of the common fruit, or is merely adjacent to it. On the other hand, the botanical sense includes many structures that are not commonly called "fruits", such as bean pods, corn kernels, wheat grains, tomatoes, and many more. However, there are several variants of the biological definition of fruit that emphasize different aspects of the enormous variety that is found among plant fruits.[2] Fruits (in either sense of the word) are the means by which many plants disseminate seeds. Most edible fruits, in particular, were evolved by plants in order to exploit animals as a means for seed dispersal, and many animals (including humans to some extent) have become dependent on fruits as a source of food.[3] Fruits account for a substantial fraction of world's agricultural output, and some (such as the apple and the pomegranate) have acquired extensive cultural and symbolic meanings. Contents [hide] 1 Botanic fruit and culinary fruit 2 Fruit development 2.1 Simple fruit 2.2 Aggregate fruit 2.3 Multiple fruits 2.4 Fruit chart 3 Seedless fruits 4 Seed dissemination 5 Uses 5.1 Nutritional value 5.2 Nonfood uses 6 Safety 7 Storage 8 See also 9 References 10 External links Botanic fruit and culinary fruit Euler diagram representing the relationship between (culinary) vegetables and botanical fruits. Some vegetables, such as tomatoes, fall into both categories. Many fruits that, in a botanical sense, are true fruits are actually treated as vegetables in cooking and food preparation, because they are not particularly sweet. These culinary vegetables include cucurbits (e.g., squash, pumpkin, and cucumber), tomatoes, peas, beans, corn, eggplant, and sweet pepper. In addition, some spices, such as allspice and chilies, are fruits, botanically speaking.[4] In contrast, occasionally a culinary "fruit" is not a true fruit in the botanical sense. For example, rhubarb is often referred to as a fruit, because it is used to make sweet desserts such as pies, though only the petiole of the rhubarb plant is edible.[5] In the culinary sense of these words, a fruit is usually any sweet-tasting plant product, especially those associated with seed(s), a vegetable is any savoury or less sweet plant product, and a nut is any hard, oily, and shelled plant product.[6] Technically, a cereal grain is also a kind of fruit, a kind which is termed a caryopsis. However, the fruit wall is very thin, and is fused to the seed coat, so almost all of the edible grain is actually a seed. Therefore, cereal grains, such as corn, wheat and rice are better considered as edible seeds, although some references do list them as fruits.[7] Edible gymnosperm seeds are often misleadingly given fruit names, e.g., pine nuts, ginkgo nuts, and juniper berries. Fruit development The development sequence of a typical drupe, the nectarine (Prunus persica) over a 7.5 month period, from bud formation in early winter to fruit ripening in midsummer (see image page for further information) Main article: Fruit anatomy A fruit results from maturation of one or more flowers, and the gynoecium of the flower(s) forms all or part of the fruit.[8] Inside the ovary/ovaries are one or more ovules where the megagametophyte contains the mega gamete or egg cell.[9] After double fertilization, these ovules will become seeds. The ovules are fertilized in a process that starts with pollination, which involves the movement of pollen from the stamens to the stigma of flowers. After pollination, a tube grows from the pollen through the stigma into the ovary to the ovule and two sperm are transferred from the pollen to the megagametophyte. Within the megagametophyte one of the two sperm unites with the egg, forming a zygote, and the second sperm enters the central cell forming the endosperm mother cell, which completes the double fertilization process.[10][11] Later the zygote will give rise to the embryo of the seed, and the endosperm mother cell will give rise to endosperm, a nutritive tissue used by the embryo. As the ovules develop into seeds, the ovary begins to ripen and the ovary wall, the pericarp, may become fleshy (as in berries or drupes), or form a hard outer covering (as in nuts). In some multiseeded fruits, the extent to which the flesh develops is proportional to the number of fertilized ovules.[12] The pericarp is often differentiated into two or three distinct layers called the exocarp (outer layer, also called epicarp), mesocarp (middle layer), and endocarp (inner layer). In some fruits, especially simple fruits derived from an inferior ovary, other parts of the flower (such as the floral tube, including the petals, sepals, and stamens), fuse with the ovary and ripen with it. In other cases, the sepals, petals and/or stamens and style of the flower fall off. When such other floral parts are a significant part of the fruit, it is called an accessory fruit. Since other parts of the flower may contribute to the structure of the fruit, it is important to study flower structure to understand how a particular fruit forms.[1] Fruits are so diverse that it is difficult to devise a classification scheme that includes all known fruits. Many common terms for seeds and fruit are incorrectly applied, a fact that complicates understanding of the terminology. Seeds are ripened ovules; fruits are the ripened ovaries or carpels that contain the seeds. To these two basic definitions can be added the clarification that in botanical terminology, a nut is not a type of fruit and not another term for seed, on the contrary to common terminology.[4] There are three general modes of fruit development: Apocarpous fruits develop from a single flower having one or more separate carpels, and they are the simplest fruits. Syncarpous fruits develop from a single gynoecium having two or more carpels fused together. Multiple fruits form from many different flowers. Plant scientists have grouped fruits into three main groups, simple fruits, aggregate fruits, and composite or multiple fruits.[13] The groupings are not evolutionarily relevant, since many diverse plant taxa may be in the same group, but reflect how the flower organs are arranged and how the fruits develop. Simple fruit Epigynous berries are simple fleshy fruit. From top right: cranberries, lingonberries, blueberries red huckleberries Simple fruits can be either dry or fleshy, and result from the ripening of a simple or compound ovary in a flower with only one pistil. Dry fruits may be either dehiscent (opening to discharge seeds), or indehiscent (not opening to discharge seeds).[14] Types of dry, simple fruits, with examples of each, are: achene - Most commonly seen in aggregate fruits (e.g. strawberry) capsule – (Brazil nut) caryopsis – (wheat) Cypsela - An achene-like fruit derived from the individual florets in a capitulum (e.g. dandelion). fibrous drupe – (coconut, walnut) follicle – is formed from a single carpel, and opens by one suture (e.g. milkweed). More commonly seen in aggregate fruits (e.g. magnolia) legume – (pea, bean, peanut) loment - a type of indehiscent legume nut – (hazelnut, beech, oak acorn) samara – (elm, ash, maple key) schizocarp – (carrot seed) silique – (radish seed) silicle – (shepherd's purse) utricle – (beet) Lilium unripe capsule fruit Fruits in which part or all of the pericarp (fruit wall) is fleshy at maturity are simple fleshy fruits. Types of fleshy, simple fruits (with examples) are: berry – (redcurrant, gooseberry, tomato, cranberry) stone fruit or drupe (plum, cherry, peach, apricot, olive) Dewberry flowers. Note the multiple pistils, each of which will produce a drupelet. Each flower will become a blackberry-like aggregate fruit. An aggregate fruit, or etaerio, develops from a single flower with numerous simple pistils.[15] Magnolia and Peony, collection of follicles developing from one flower. Tuliptree, collection of samaras. Sweet gum, collection of capsules. Sycamore, collection of achenes. Teasel, collection of cypsellas The pome fruits of the family Rosaceae, (including apples, pears, rosehips, and saskatoon berry) are a syncarpous fleshy fruit, a simple fruit, developing from a half-inferior ovary.[16] Schizocarp fruits form from a syncarpous ovary and do not really dehisce, but split into segments with one or more seeds; they include a number of different forms from a wide range of families.[13] Carrot seed is an example. Aggregate fruit Detail of raspberry flower. Aggregate fruits form from single flowers that have multiple carpels which are not joined together, i.e. each pistil contains one carpel. Each pistil forms a fruitlet, and collectively the fruitlets are called an etaerio. Four types of aggregate fruits include etaerios of achenes, follicles, drupelets, and berries. Ranunculaceae species, including Clematis and Ranunculus have an etaerio of achenes, Calotropis has an etaerio of follicles, and Rubus species like raspberry, have an etaerio of drupelets. Annona have Etaerio of berries.[17][18] The raspberry, whose pistils are termed drupelets because each is like a small drupe attached to the receptacle. In some bramble fruits (such as blackberry) the receptacle is elongated and part of the ripe fruit, making the blackberry an aggregate-accessory fruit.[19] The strawberry is also an aggregate-accessory fruit, only one in which the seeds are contained in achenes.[20] In all these examples, the fruit develops from a single flower with numerous pistils. Multiple fruits Main article: Multiple fruit A multiple fruit is one formed from a cluster of flowers (called an inflorescence). Each flower produces a fruit, but these mature into a single mass.[21] Examples are the pineapple, fig, mulberry, osage-orange, and breadfruit. In some plants, such as this noni, flowers are produced regularly along the stem and it is possible to see together examples of flowering, fruit development, and fruit ripening. In the photograph on the right, stages of flowering and fruit development in the noni or Indian mulberry (Morinda citrifolia) can be observed on a single branch. First an inflorescence of white flowers called a head is produced. After fertilization, each flower develops into a drupe, and as the drupes expand, they become connate (merge) into a multiple fleshy fruit called a syncarpet. Fruit chart To summarize common types of fleshy fruit (examples follow in the table below): Berry – simple fruit and seeds created from a single ovary Pepo – Berries where the skin is hardened, like cucurbits Hesperidium – Berries with a rind and a juicy interior, like most citrus fruit Compound fruit, which includes: Aggregate fruit – with seeds from different ovaries of a single flower Multiple fruit – fruits of separate flowers, merged or packed closely together Accessory fruit – where some or all of the edible part is not generated by the ovary Types of fleshy fruits True berry Pepo Hesperidium Aggregate fruit Multiple fruit Accessory fruit Blackcurrant, Redcurrant, Gooseberry, Tomato, Eggplant, Guava, Lucuma, Chili pepper, Pomegranate, Kiwifruit, Grape, Cranberry, Blueberry Pumpkin, Gourd, Cucumber, Melon Orange, Lemon, Lime, Grapefruit Blackberry, Raspberry, Boysenberry Pineapple, fig, Mulberry, Hedge apple Gaultheria procumbens, Strawberry Seedless fruits An arrangement of fruits commonly thought of as vegetables, including tomatoes and various squash Seedlessness is an important feature of some fruits of commerce. Commercial cultivars of bananas and pineapples are examples of seedless fruits. Some cultivars of citrus fruits (especially navel oranges), satsumas, mandarin oranges, table grapes, grapefruit, and watermelons are valued for their seedlessness. In some species, seedlessness is the result of parthenocarpy, where fruits set without fertilization. Parthenocarpic fruit set may or may not require pollination but most seedless citrus fruits require stimulus from pollination to produce fruit. Seedless bananas and grapes are triploids, and seedlessness results from the abortion of the embryonic plant that is produced by fertilization, a phenomenon known as stenospermocarpy which requires normal pollination and fertilization.[22] Seed dissemination Variations in fruit structures largely depend on the mode of dispersal of the seeds they contain. This dispersal can be achieved by animals, wind, water, or explosive dehiscence.[23] Some fruits have coats covered with spikes or hooked burrs, either to prevent themselves from being eaten by animals or to stick to the hairs, feathers or legs of animals, using them as dispersal agents. Examples include cocklebur and unicorn plant.[24][25] The sweet flesh of many fruits is "deliberately" appealing to animals, so that the seeds held within are eaten and "unwittingly" carried away and deposited at a distance from the parent. Likewise, the nutritious, oily kernels of nuts are appealing to rodents (such as squirrels) who hoard them in the soil in order to avoid starving during the winter, thus giving those seeds that remain uneaten the chance to germinate and grow into a new plant away from their parent.[4] Other fruits are elongated and flattened out naturally and so become thin, like wings or helicopter blades, e.g. maple, tuliptree and elm. This is an evolutionary mechanism to increase dispersal distance away from the parent via wind. Other wind-dispersed fruit have tiny parachutes, e.g. dandelion and salsify.[23] Coconut fruits can float thousands of miles in the ocean to spread seeds. Some other fruits that can disperse via water are nipa palm and screw pine.[23] Some fruits fling seeds substantial distances (up to 100 m in sandbox tree) via explosive dehiscence or other mechanisms, e.g. impatiens and squirting cucumber.[26] Uses Nectarines are one of many fruits that can be easily stewed. Oranges, bananas, pears, apples, and a watermelon Fruit bowl containing pomegranate, pears, apples, bananas, an orange and a guava Many hundreds of fruits, including fleshy fruits like apple, peach, pear, kiwifruit, watermelon and mango are commercially valuable as human food, eaten both fresh and as jams, marmalade and other preserves. Fruits are also in manufactured foods like cookies, muffins, yoghurt, ice cream, cakes, and many more. Many fruits are used to make beverages, such as fruit juices (orange juice, apple juice, grape juice, etc.) or alcoholic beverages, such as wine or brandy.[27] Apples are often used to make vinegar. Fruits are also used for gift giving, Fruit Basket and Fruit Bouquet are some common forms of fruit gifts. Many vegetables are botanical fruits, including tomato, bell pepper, eggplant, okra, squash, pumpkin, green bean, cucumber and zucchini.[28] Olive fruit is pressed for olive oil. Spices like vanilla, paprika, allspice and black pepper are derived from berries.[29] Nutritional value Fruits are generally high in fiber, water, vitamin C and sugars, although this latter varies widely from traces as in lime, to 61% of the fresh weight of the date.[30] Fruits also contain various phytochemicals that do not yet have an RDA/RDI listing under most nutritional factsheets, and which research indicates are required for proper long-term cellular health and disease prevention. Regular consumption of fruit is associated with reduced risks of cancer, cardiovascular disease (especially coronary heart disease), stroke, Alzheimer disease, cataracts, and some of the functional declines associated with aging.[31] Diets that include a sufficient amount of potassium from fruits and vegetables also help reduce the chance of developing kidney stones and may help reduce the effects of bone-loss. Fruits are also low in calories which would help lower ones calorie intake as part of a weight loss diet.[32] Nonfood uses Because fruits have been such a major part of the human diet, different cultures have developed many different uses for various fruits that they do not depend on as being edible. Many dry fruits are used as decorations or in dried flower arrangements, such as unicorn plant, lotus, wheat, annual honesty and milkweed. Ornamental trees and shrubs are often cultivated for their colorful fruits, including holly, pyracantha, viburnum, skimmia, beautyberry and cotoneaster.[33] Fruits of opium poppy are the source of opium which contains the drugs morphine and codeine, as well as the biologically inactive chemical theabaine from which the drug oxycodone is synthysized.[34] Osage orange fruits are used to repel cockroaches.[35] Bayberry fruits provide a wax often used to make candles.[36] Many fruits provide natural dyes, e.g. walnut, sumac, cherry and mulberry.[37] Dried gourds are used as decorations, water jugs, bird houses, musical instruments, cups and dishes. Pumpkins are carved into Jack-o'-lanterns for Halloween. The spiny fruit of burdock or cocklebur were the inspiration for the invention of Velcro.[38] Coir is a fibre from the fruit of coconut that is used for doormats, brushes, mattresses, floortiles, sacking, insulation and as a growing medium for container plants. The shell of the coconut fruit is used to make souvenir heads, cups, bowls, musical instruments and bird houses.[39] Fruit is often used as a subject of still life paintings. Safety For food safety, the CDC recommends proper fruit handling and preparation to reduce the risk of food contamination and foodborne illness. Fresh fruits and vegetables should carefully be selected. At the store, they should not be damaged or bruised and pre-cut pieces should be refrigerated or surrounded by ice. All fruits and vegetables should be rinsed before eating. This recommendation also applies to produce with rinds or skins that are not eaten. It should be done just before preparing or eating to avoid premature spoilage. Fruits and vegetables should be kept separate from raw foods like meat, poultry, and seafood, as well as utensils that have come in contact with raw foods. Fruits and vegetables, if they are not going to be cooked, should be thrown away if they have touched raw meat, poultry, seafood or eggs. All cut, peeled, or cooked fruits and vegetables should be refrigerated within two hours. After a certain time, harmful bacteria may grow on them and increase the risk of foodborne illness.[40] Storage The plant hormone ethylene causes ripening of many types of fruit. Maintaining most fruits in an efficient cold chain is optimal for post harvest storage, with the aim of extending and ensuring shelf life. All fruits benefit from proper post harvest care.[41] See also Fruit tree Fruitarianism List of culinary fruits References ^ a b Mauseth, James D. (April 1, 2003). Botany: An Introduction to Plant Biology. Jones and Bartlett. pp. 271–272. ISBN 0-7637-2134-4. ^ Schlegel, Rolf H J (January 1, 2003). Encyclopedic Dictionary of Plant Breeding and Related Subjects. Haworth Press. p. 177. ISBN 1-56022-950-0. ^ Lewis, Robert A. (January 1, 2002). CRC Dictionary of Agricultural Sciences. CRC Press. ISBN 0-8493-2327-4. ^ a b c McGee, Harold (November 16, 2004). On Food and Cooking: The Science and Lore of the Kitchen. Simon and Schuster. pp. 247–248. ISBN 0-684-80001-2. ^ McGee (2004-11-16). On Food and Cooking. p. 367. ISBN 9780684800011. ^ For a Supreme Court of the United States ruling on the matter, see Nix v. Hedden. ^ Lewis (2002). CRC Dictionary of Agricultural Sciences. p. 238. ISBN 9780849323270. ^ Esau, K. 1977. Anatomy of seed plants. John Wiley and Sons, New York. ^ http://www.palaeos.com/Plants/Lists/Glossary/GlossaryL.html#M ^ Mauseth, James D. (2003). Botany: an introduction to plant biology. Boston: Jones and Bartlett Publishers. p. 258. ISBN 978-0-7637-2134-3. ^ Rost, Thomas L.; Weier, T. Elliot; Weier, Thomas Elliot (1979). Botany: a brief introduction to plant biology. New York: Wiley. pp. 135–37. ISBN 0-471-02114-8. ^ Mauseth (2003-04-25). Botany. Chapter 9: Flowers and Reproduction. ISBN 9780763721343. ^ a b Singh, Gurcharan (2004). Plants Systematics: An Integrated Approach. Science Publishers. p. 83. ISBN 1-57808-351-6. ^ Schlegel (2003-05-13). Encyclopedic Dictionary. p. 123. ISBN 9781560229506. ^ Schlegel (2003-05-13). Encyclopedic Dictionary. p. 16. ISBN 9781560229506. ^ Evolutionary trends in flowering plants. New York: Columbia University Press. 1991. p. 209. ISBN 0-231-07328-3. ^ Gupta, Prof. P.K.. Introduction to Biology. 2134. ISBN 9788171338962 ^ http://www.rkv.rgukt.in/content/Biology/47Module/47fruit.pdf ^ McGee (2004-11-16). On Food and Cooking. pp. 361–362. ISBN 9780684800011. ^ McGee (2004-11-16). On Food and Cooking. pp. 364–365. ISBN 9780684800011. ^ Schlegel (2003-05-13). Encyclopedic Dictionary. p. 282. ISBN 9781560229506. ^ Spiegel-Roy, P.; E. E. Goldschmidt (August 28, 1996). The Biology of Citrus. Cambridge University Press. pp. 87–88. ISBN 0-521-33321-0. ^ a b c Capon, Brian (February 25, 2005). Botany for Gardeners. Timber Press. pp. 198–199. ISBN 0-88192-655-8. ^ Heiser, Charles B. (April 1, 2003). Weeds in My Garden: Observations on Some Misunderstood Plants. Timber Press. pp. 93–95. ISBN 0-88192-562-4. ^ Heiser (2003-04-01). Weeds in My Garden. pp. 162–164. ISBN 9780881925623. ^ Feldkamp, Susan (2002). Modern Biology. Holt, Rinehart, and Winston. p. 634. ISBN 0-88192-562-4. ^ McGee (2004-11-16). On Food and Cooking. Chapter 7: A Survey of Common Fruits. ISBN 9780684800011. ^ McGee (2004-11-16). On Food and Cooking. Chapter 6: A Survey of Common Vegetables. ISBN 9780684800011. ^ Farrell, Kenneth T. (November 1, 1999). Spices, Condiments and Seasonings. Springer. pp. 17–19. ISBN 0-8342-1337-0. ^ Hulme, A.C (editor) (1970). The Biochemistry of Fruits and their Products. Volume 1. London & New York: Academic Press ^ Health benefits of fruit and vegetables are from additive and synergistic combinations of phytochemicals - Liu 78 (3): 517S - American Journal of Clinical Nutrition ^ "Why is it Important to eat Fruit?". ^ Adams, Denise Wiles (February 1, 2004). Restoring American Gardens: An Encyclopedia of Heirloom Ornamental Plants, 1640-1940. Timber Press. ISBN 0-88192-619-1. ^ Booth, Martin (June 12, 1999). Opium: A History. St. Martin's Press. ISBN 0-312-20667-4. ^ Cothran, James R. (November 1, 2003). Gardens and Historic Plants of the Antebellum South. University of South Carolina Press. p. 221. ISBN 1-57003-501-6. ^ K, Amber (December 1, 2001). Candlemas: Feast of Flames. Llewellyn Worldwide. p. 155. ISBN 0-7387-0079-7. ^ Adrosko, Rita J. (June 1, 1971). Natural Dyes and Home Dyeing: A Practical Guide with over 150 Recipes. Courier Dover Publications. ISBN 0-486-22688-3. ^ Wake, Warren (March 13, 2000). Design Paradigms: A Sourcebook for Creative Visualization. John Wiley and Sons. pp. 162–163. ISBN. ISBN 9780471299769. ^ "The Many Uses of the Coconut". The Coconut Museum. Retrieved 2006-09-14. ^ Food Safety Basics for Fruits and Vegetables at the Centers for Disease Control and Prevention ^ Why Cold Chain for Fruits: Kohli, Pawanexh (2008). "Fruits and Vegetables Post-Harvest Care: The Basics". Crosstree Techno-visors. Tree From Wikipedia, the free encyclopedia For other uses, see Tree (disambiguation). Trees on a mountain in northern Utah during early autumn Trunk base of a Coast Redwood tree in Jedediah Smith Redwoods State Park: Simpson Reed Discovery Trail, near Crescent City, California A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance.[1] A minimum height specification at maturity is cited by some authors, varying from 3 m[2] to 6 m;[3] some authors set a minimum of 10 cm trunk diameter (30 cm girth).[4] Woody plants that do not meet these definitions by having multiple stems and/or small size are called shrubs. Compared with most other plants, trees are long-lived, some reaching several thousand years old and growing to up to 115 m (379 ft) high.[5] Trees are an important component of the natural landscape because of their prevention of erosion and the provision of a weather-sheltered ecosystem in and under their foliage. They also play an important role in producing oxygen and reducing carbon dioxide in the atmosphere, as well as moderating ground temperatures. They are also elements in landscaping and agriculture, both for their aesthetic appeal and their orchard crops (such as apples). Wood from trees is a building material, as well as a primary energy source in many developing countries. Trees also play a role in many of the world's mythologies (see trees in mythology).[6] Contents [hide] 1 Classification 2 Morphology 3 Record breaking trees 3.1 Tallest trees 3.2 Stoutest trees 3.3 Largest trees 3.4 Smallest tree 3.5 Oldest trees 4 Damage 5 Trees in culture 6 Tree value estimation 7 See also 8 References 8.1 Notes 8.2 Bibliography 9 External links Classification A Sweet Chestnut tree in Ticino, Switzerland A tree is a plant form that occurs in many different orders and families of plants. Trees show a variety of growth forms, leaf type and shape, bark characteristics and reproductive organs. The tree form has evolved separately in unrelated classes of plants, in response to similar environmental challenges, making it a classic example of parallel evolution. With an estimate of 100,000 tree species, the number of tree species worldwide might total 25 percent of all living plant species.[7] The majority of tree species grow in tropical regions of the world and many of these areas have not been surveyed yet by botanists, making species diversity and ranges poorly understood.[8] Tropical tree in Campeche, Mexico The earliest trees were tree ferns, horsetails and lycophytes, which grew in forests in the Carboniferous period; tree ferns still survive, but the only surviving horsetails and lycophytes are not of tree form. Later, in the Triassic period, conifers, ginkgos, cycads and other gymnosperms appeared, and subsequently flowering plants in the Cretaceous period. Most species of trees today are flowering plants (Angiosperms) and conifers. For the listing of examples of well-known trees and how they are classified, see List of tree genera. A small group of trees growing together is called a grove or copse, and a landscape covered by a dense growth of trees is called a forest. Several biotopes are defined largely by the trees that inhabit them; examples are rainforest and taiga (see ecozones). A landscape of trees scattered or spaced across grassland (usually grazed or burned over periodically) is called a savanna. A forest of great age is called old growth forest or ancient woodland (in the UK). A young tree is called a sapling. Morphology Beech leaves Tree roots anchor the structure and provide water and nutrients. The ground has eroded away around the roots of this young pine tree. The parts of a tree are the roots, trunk(s), branches, twigs and leaves. Tree stems consist mainly of support and transport tissues (xylem and phloem). Wood consists of xylem cells, and bark is made of phloem and other tissues external to the vascular cambium. Trees may be grouped into exogenous and endogenous trees according to the way in which their stem diameter increases. Exogenous trees, which comprise the great majority of trees (all conifers, and almost all broadleaf trees), grow by the addition of new wood outwards, immediately under the bark. Endogenous trees, mainly in the monocotyledons (e.g., palms and dragon trees), but also cacti, grow by addition of new material inwards.[clarification needed] As an exogenous tree grows, it creates growth rings as new wood is laid down concentrically over the old wood. In species growing in areas with seasonal climate changes, wood growth produced at different times of the year may be visible as alternating light and dark, or soft and hard, rings of wood.[3] In temperate climates, and tropical climates with a single wet-dry season alternation, the growth rings are annual, each pair of light and dark rings being one year of growth; these are known as annual rings. In areas with two wet and dry seasons each year, there may be two pairs of light and dark rings each year; and in some (mainly semi-desert regions with irregular rainfall), there may be a new growth ring with each rainfall.[9] In tropical rainforest regions, with constant year-round climate, growth is continuous and the growth rings are not visible nor is there a change in the wood texture. In species with annual rings, these rings can be counted to determine the age of the tree, and used to date cores or even wood taken from trees in the past, a practice known as the science of dendrochronology. Very few tropical trees can be accurately dated in this manner. Age determination is also impossible in endogenous trees. The roots of a tree are generally embedded in earth, providing anchorage for the above-ground biomass and absorbing water and nutrients from the soil. However, while ground nutrients are essential to a tree's growth the majority of its biomass comes from carbon dioxide absorbed from the atmosphere (see photosynthesis). Above ground, the trunk gives height to the leaf-bearing branches, aiding in competition with other plant species for sunlight. In many trees, the arrangement of the branches optimizes exposure of the leaves to sunlight. Not all trees have all the plant organs or parts mentioned above. For example, most palm trees are not branched, the saguaro cactus of North America has no functional leaves, tree ferns do not produce bark, etc. Based on their general shape and size, all of these are nonetheless generally regarded as trees. A plant form that is similar to a tree, but generally having smaller, multiple trunks and/or branches that arise near the ground, is called a shrub. However, no precise differentiation between shrubs and trees is possible. Given their small size, bonsai plants would not technically be 'trees', but one should not confuse reference to the form of a species with the size or shape of individual specimens. A spruce seedling does not fit the definition of a tree, but all spruces are trees. Record breaking trees The world's champion trees can be rated on height, trunk diameter or girth, total size, and age. Tallest trees The heights of the tallest trees in the world have been the subject of considerable dispute and much exaggeration. Modern verified measurements with laser rangefinders, other measuring devices, or with tape drop measurements made by tree climbers (such as those carried out by canopy researchers or members of groups like the U.S. Eastern Native Tree Society), have shown that some older measuring methods and measurements are often unreliable, sometimes producing exaggerations of 5% to 15% or more above the real height. Historical claims of trees growing to 130 m (427 ft), and even 150 m (492 ft), are now largely disregarded as unreliable, and attributed to human error. Historical records of fallen trees measured prostrate on the ground are considered to be somewhat more reliable. The following are now accepted as the top ten tallest reliably measured species: Coast Redwood (Sequoia sempervirens): 115.56 m (379.1 ft), Redwood National Park, California, United States[10] Australian Mountain-ash (Eucalyptus regnans): 99.6 m (326.8 ft), south of Hobart, Tasmania, Australia[11] Coast Douglas-fir (Pseudotsuga menziesii): 99.4 m (326.1 ft), Brummit Creek, Coos County, Oregon, United States[12] Sitka Spruce (Picea sitchensis): 96.7 m (317.3 ft), Prairie Creek Redwoods State Park, California, United States[13] Giant Sequoia (Sequoiadendron giganteum): 94.9 m (311.4 ft), Redwood Mountain Grove, Kings Canyon National Park, California, United States[14] Tasmanian Blue Gum (Eucalyptus globulus): 90.7 m (297.6 ft), Tasmania, Australia[15] Manna Gum (Eucalyptus viminalis): 89 m (292 ft), Evercreech Forest Reserve, Tasmania, Australia[15] Shorea faguetiana: 88.3 m (289.7 ft) Tawau Hills National Park, in Sabah on the island of Borneo[16] Alpine Ash (Eucalyptus delegatensis): 87.9 m (288.4 ft), Tasmania, Australia[15] Noble Fir (Abies procera): 87.5 m (287.1 ft) Mount St. Helens National Volcanic Monument, Washington, United States[17][18] A view of a tree from below; this may exaggerate apparent height Stoutest trees The girth of a tree is usually much easier to measure than the height, as it is a simple matter of stretching a tape round the trunk, and pulling it taut to find the circumference. Despite this, UK tree author Alan Mitchell made the following comment about measurements of yew trees: The aberrations of past measurements of yews are beyond belief. For example, the tree at Tisbury has a well-defined, clean, if irregular bole at least 1.5 m long. It has been found to have a girth that dilated and shrunk in the following way: 11.28 m (1834 Loudon), 9.3 m (1892 Lowe), 10.67 m (1903 Elwes and Henry), 9.0 m (1924 E. Swanton), 9.45 m (1959 Mitchell) ... Earlier measurements have therefore been omitted." As a general standard, tree girth is taken at 'breast height'. This is cited as dbh (diameter at breast height) in tree and forestry literature.[3][19] Breast height is defined differently in different situations, with most forestry measurements taking girth at 1.3 m above ground,[19] while those who measure ornamental trees usually measure at 1.5 m above ground;[3] in most cases this makes little difference to the measured girth. On sloping ground, the "above ground" reference point is usually taken as the highest point on the ground touching the trunk,[3][19] but some use the average between the highest and lowest points of ground[citation needed]. Some of the inflated old measurements may have been taken at ground level. Some past exaggerated measurements also result from measuring the complete next-to-bark measurement, pushing the tape in and out over every crevice and buttress.[20] Modern trends are to cite the tree's diameter rather than the circumference. Diameter of the tree is calculated by finding the medium diameter of the trunk, in most cases obtained by dividing the measured circumference by π; this assumes the trunk is mostly circular in cross-section (an oval or irregular cross-section would result in a mean diameter slightly greater than the assumed circle). Accurately measuring circumference or diameter is difficult in species with the large buttresses that are especially characteristic in many species of rainforest trees. Simple measurement of circumference of such trees can be misleading when the circumference includes much empty space between buttresses. One further problem with measuring baobabs Adansonia is that these trees store large amounts of water in the very soft wood in their trunks. This leads to marked variation in their girth over the year (though not more than about 2.5%[21]), swelling to a maximum at the end of the rainy season, minimum at the end of the dry season. The stoutest living single-trunk species in diameter are: African Baobab Adansonia digitata: 15.9 m (52 ft), Glencoe Baobab (measured near the ground), Limpopo Province, South Africa.[22] This tree split up[clarification needed] in November 2009 and now the stoutest baobab could be Sunland Baobab (South Africa) with idealised diameter 10.64 m and correct circumference - 33.4 m. Montezuma Cypress Taxodium mucronatum: 11.62 m (38.1 ft), Árbol del Tule, Santa Maria del Tule, Oaxaca, Mexico.[23] Note though that this diameter includes buttressing; the actual idealised diameter of the area of its wood is 9.38 m (30.8 ft).[23] Giant Sequoia Sequoiadendron giganteum: 8.85 m (29 ft), General Grant tree, General Grant Grove, California, United States[24] Coast Redwood Sequoia sempervirens: 7.9 m (25.9 ft), Lost Monarch Jedediah Smith Redwoods State Park, California, United States. Australian Oak Eucalyptus obliqua: 6.72 m (22 ft) Australian Mountain-ash Eucalyptus regnans: 6.52 m (21.4 ft), Big Foot Western Redcedar Thuja plicata: 5.99 m (19.7 ft), Kalaloch Cedar, Olympic National Park Sitka Spruce Picea sitchensis: 5.39 m (17.7 ft), Quinalt Lake Spruce, Olympic National Park Alerce Fitzroya cupressoides: 5.0 m (16.4 ft) An additional problem lies in instances where multiple trunks (whether from an individual tree or multiple trees) grow together. The Sacred Fig is a notable example of this, forming additional 'trunks' by growing adventitious roots down from the branches, which then thicken up when the root reaches the ground to form new trunks; a single Sacred Fig tree can have hundreds of such trunks.[1] Largest trees The coniferous Coast Redwood is the tallest tree species on earth. The largest trees in total volume are both tall and large in diameter and, in particular, hold a large diameter high up the trunk. Measurement is very complex, particularly if branch volume is to be included as well as the trunk volume, so measurements have only been made for a small number of trees, and generally only for the trunk. No attempt has ever been made to include root volume. Measuring standards vary. The top ten species measured so far are*: Giant Sequoia Sequoiadendron giganteum: 1,487 m³ (52,508 cu ft), General Sherman[25] Coast Redwood Sequoia sempervirens: 1,203 m³ (42,500 cu ft), Lost Monarch[17] Montezuma Cypress Taxodium mucronatum: 750 m³ (25,000 cu ft), Árbol del Tule[26] Western Redcedar Thuja plicata: 500 m³ (17,650 cu ft ), Quinault Lake Redcedar[25] Tasmanian Blue Gum Eucalyptus globulus: 368 m³ (13,000 cu ft), Rullah Longatyle (Strong Girl, also Grieving Giant) [15] Australian Mountain-ash Eucalyptus regnans: 360 m³ (12,714 cu ft), Arve Big Tree[15] Coast Douglas-fir Pseudotsuga menziesii 349 m³ (12,320 cu ft) Red Creek Tree Sitka Spruce Picea sitchensis 337 m³ (11,920 cu ft) Queets Spruce Australian Oak Eucalyptus obliqua: 337 m³ (11,920 cu ft) Gothmog[15] Alpine Ash Eucalyptus delegatensis: 286 m³ (10,100 cu ft), located in Styx River Valley[15] (*)This list does not take into account now dead specimens. Smallest tree Many fully grown mature trees may be very short due to environmental factors or disease. However healthy and well grown specimens of a few species of tree only reach a height of a few centimetres. Amongst these is Lepidothamnus laxifolius believed to be the shortest conifer in the world. Oldest trees The oldest trees are determined by growth rings, which can be seen if the tree is cut down, or in cores taken from the bark to the center of the tree. Accurate determination is only possible for trees that produce growth rings, generally those in seasonal climates. Trees in uniform non-seasonal tropical climates grow continuously and do not have distinct growth rings. It is also only possible for trees that are solid to the center. Many very old trees become hollow as the dead heartwood decays. For some of these species, age estimates have been made on the basis of extrapolating current growth rates, but the results are usually largely speculation. White (1998)[27] proposes a method of estimating the age of large and veteran trees in the United Kingdom through the correlation between a tree's stem diameter, growth character and age. The verified oldest measured ages are: Great Basin Bristlecone Pine (Methuselah) Pinus longaeva: 4,844 years[28] Alerce Fitzroya cupressoides: 3,622 years[28] Giant Sequoia Sequoiadendron giganteum: 3,266 years[28] Sugi Cryptomeria japonica: 3,000 years[29] Huon-pine Lagarostrobos franklinii: 2,500 years[28] Other species suspected of reaching exceptional age include European Yew Taxus baccata (probably over 2,000 years[30][31]) and Western Redcedar Thuja plicata. The oldest known European Yew is the Llangernyw Yew in the Churchyard of Llangernyw village in North Wales, which is estimated to be between 4,000 and 5,000 years old. The oldest reported age for an angiosperm tree is 2293 years for the Sri Maha Bodhi Sacred Fig (Ficus religiosa) planted in 288 BC at Anuradhapura, Sri Lanka. This is also the oldest human-planted tree with a known planting date.[citation needed] Damage El Grande, about 280 feet high, the most massive (though not the tallest) Eucalyptus regnans was accidentally killed by loggers burning-off the remains of legally loggable trees (less than 280 ft) that had been felled all around it. The two sources of tree damage are either biotic (from living sources) or abiotic (from non-living sources). Biotic sources include insects that bore into the tree, deer that rub bark off, and fungi.[32] Abiotic sources include lightning, vehicles impacts, and construction activities. Construction activities can involve a number of damage sources, including grade changes that prevent aeration to roots, spills involving toxic chemicals such as cement or petroleum products, or severing of branches or roots. Both damage sources can result in trees becoming dangerous, and the term "hazard trees" is commonly used by arborists, and industry groups such as power line operators. Hazard trees are trees that, due to disease or other factors, are more susceptible to falling in windstorms, or having parts of the tree fall. Evaluating the danger a tree presents is based on a process called the Quantified Tree Risk Assessment.[33] Assessment as to labeling a tree a hazard tree can be based on a field examination. Assessment as a result of construction activities that will damage a tree is based on three factors: severity, extent and duration. Severity relates usually to the degree of intrusion into the TPZ and resultant root loss. Extent is frequently a percentage of a factor such as canopy, roots or bark, and duration is normally based on time. Root severing is considered permanent in time. Trees are similar to people. Both can withstand massive amounts of some types of damage and survive, but even small amounts of certain types of trauma can result in death. Arborists are very aware that established trees will not tolerate any appreciable disturbance of the root system.[34] However, lay people and construction professionals are seldom cognizant of how easily a tree can be killed. One reason for confusion about tree damage from construction involves the dormancy of trees during winter. Another factor is that trees may not show symptoms of damage until 24 months or longer after damage has occurred. For that reason, persons uneducated in arboriculture science may not correlate the actual cause and resultant effect. Various organizations, such as the International Society of Arboriculture, the British Standards Institute and the National Arborist Association (about 2007 renamed the Tree Industry Association), have long recognized the importance of construction activities that impact tree health. The impacts are important because they can result in monetary losses due to tree damage and resultant remediation or replacement costs, as well as violation of government ordinances or community or subdivision restrictions. As a result, protocols for tree management prior to, during and after construction activities are well established, tested and refined. These basic steps are involved: Review of the construction plans Development of the related tree inventory Application of standard construction tree management protocols Assessment of potential for expected tree damages Development of a tree protection plan (providing for pre-, concurrent, and post construction damage prevention and remediation steps) Development of a tree protection plan Development of a remediation plan Implementation of tree protection zones (TPZ) Assessment of construction tree damage, post-construction Implementation of the remediation plan International standards are uniform in analyzing damage potential and sizing TPZs (tree protection zones) to minimize damage. For mature to fully mature trees, the accepted TPZ comprises a 1.5-foot (0.46 m) set-off for every 1-inch (25 mm) diameter of trunk. That means for a 10-inch (250 mm) tree, the TPZ would extend 15 feet (4.6 m) in all directions from the base of the trunk at ground level. For young or small trees with minimal crowns (and trunks less than 4 inches (100 mm) in diameter) a TPZ equal to 1-foot (0.30 m) for every inch of trunk diameter may suffice. That means for a 3-inch (76 mm) tree, the TPZ would extend 3 feet (0.91 m) in all directions from the base of the trunk at ground level. Detailed information on TPZs and related topics is available at minimal cost from organizations like the International Society for Arboriculture. Trees in culture Main article: Tree (mythology) The tree has always been a cultural symbol. Common icons are the World tree, for instance Yggdrasil,[35] and the tree of life. The tree is often used to represent nature or the environment itself. A common misconception is that trees get most of their mass from the ground.[36] In fact, 99% of a tree's mass comes from the air.[36] Tree value estimation Studies have shown that trees contribute as much as 27% of the appraised land value in certain markets.[37] See also Arboretum Axel Erlandson Christmas tree Deforestation Dendrology Dendrometry Evolution of plants#Evolution of trees Exploding tree Frost crack Fruit trees Gilroy Gardens John Krubsack List of famous trees List of tree genera List of trees and shrubs by taxonomic family Mother of the Forest Multipurpose tree Plantation Topiary Tree allometry Tree climbing Tree line Trees of the world Tree Shaping Urban forestry Woodland management References Notes ^ a b Huxley, A., ed. (1992). New RHS Dictionary of Gardening. Macmillan ISBN 0-333-47494-5. ^ Rushforth, K. (1999). Trees of Britain and Europe. Collins ISBN 0-00-220013-9. ^ a b c d e Mitchell, A. F. (1974). A Field Guide to the Trees of Britain and Northern Europe. Collins ISBN 0-00-212035-6 ^ Utkarsh Ghate. "Field Guide to Indian Trees, introductory chapter: Introduction to Common Indian Trees" (RTF). Retrieved 2007-07-25. ^ Gymnosperm Database: Sequoia sempervirens ^ Going Out On A Limb With A Tree-Person Ratio, Morning Edition, National Public Radio. 12 Nov 2008. ^ "TreeBOL project". Retrieved 2008-07-11. ^ Friis, Ib, and Henrik Balslev. 2005. Plant diversity and complexity patterns: local, regional, and global dimensions : proceedings of an international symposium held at the Royal Danish Academy of Sciences and Letters in Copenhagen, Denmark, 25–28 May 2003. Biologiske skrifter, 55. Copenhagen: Royal Danish Academy of Sciences and Letters. pp 57-59. ^ Mirov, N. T. (1967). The Genus Pinus. Ronald Press. ^ "Gymnosperm Database: Sequoia sempervirens". Retrieved 2007-06-10. "Hyperion, Redwood National Park, CA, 115.55 m" ^ "Tasmania's Ten Tallest Giants". Tasmanian Giant Trees Consultative Committee. Archived from the original on 2008-07-18. Retrieved 2009-01-07. "Height (m): 99.6; Diameter (cm): 405; Species: E. regnans; Tree identification: TT443; Name: Centurion; Location: south of Hobart; Year last measured: 2008" ^ "Gymnosperm Database: Pseudotsuga menziesii var. menziesii". Retrieved 2007-06-10. "The Brummit Fir: Height 99.4 m, dbh 354 cm, on E. Fork Brummit Creek in Coos County, Oregon; in 1998" ^ "Gymnosperm Database: Picea sitchensis". Retrieved 2007-06-10. "This tree also has a sign nearby proclaiming it to be 'the world's largest spruce'. The two tallest on record, 96.7 m and 96.4 m, are in Prairie Creek Redwoods State Park, California" ^ "Gymnosperm Database: Sequoiadendron giganteum". Retrieved 2007-06-10. "The tallest known giant sequoia is a specimen 94.9 m tall, first measured August 1998 in the Redwood Mountain Grove, California" ^ a b c d e f g [1]. "Tasmanian Giant Trees Register". Forestry Tasmania. ^ "Tallest Tropical Trees". Retrieved 2010-04-14. ^ a b Prof Stephen Sillett's webpage[dead link] with photogallery including: a general gallery, canopy views, epiphytes, and arboreal animals. ^ "The Gymnosperm Database: Abies procera". Retrieved 2010-04-14. ^ a b c Hamilton, G. J. (1975). Forest Mensuration Handbook. Forestry Commission Booklet 39. ISBN 0-11-710023-4. ^ Mitchell, A. F. (1972). Conifers in the British Isles. Forestry Commission Booklet 33. ^ Fenner, M. 1980. Some measurements on the water relations of baobab trees. Biotropica 12 (3): 205-209. ^ "List of Champion Trees published for comment, 2005, South African Department of Water Affairs and Forestry". Retrieved 2010-01-18. ^ a b Gymnosperm Database: Taxodium mucronatum ^ "Gymnosperm Database: Sequoiadendron giganteum". Retrieved 2007-06-10. "the General Grant tree in Kings Canyon National Park, CA, which is 885 cm dbh and 81.1 m tall" ^ a b "Gymnosperm Database: A Tale of Big Tree Hunting In California". Archived from the original. Error: If you specify |archiveurl=, you must also specify |archivedate=. Retrieved 2007-06-10. "Sequoiadendron giganteum is 1489 m³, Sequoia sempervirens 1045 m³, Thuja plicata 500 m³, Agathis australis ca. 400 m³" ^ "ENTSTrees - Árbol del Tule". Groups.google.com. Retrieved 2010-10-18. ^ White, J. (1990). Estimating the Age of Large and Veteran Trees in Britain. Forestry Commission Edinburgh. ^ a b c d Gymnosperm Database: How Old Is That Tree?. Retrieved on 2008-04-17. ^ Suzuki, E. 1997. The Dynamics of Old Cryptomeria japonica Forest on Yakushima Island. Tropics 6(4): 421–428. Available online ^ Harte, J. (1996). How old is that old yew? At the Edge 4: 1-9. Available online ^ Kinmonth, F. (2006). Ageing the yew - no core, no curve? International Dendrology Society Yearbook 2005: 41-46 ISSN 0307-332X ^ Wiseman, P. Eric, Integrated Pest Management Tactics, Continuing Education Unit, International Arboricultural Society Vol 17, Unit 1, February 2008 ^ Ellison, M. J. Quantified Tree Risk Assessment Used in the Management of Amenity Trees. Journal Arboric. International Society of Arboriculture, Savoy, Illinois. 31:2 57-65, 2005 ^ Schoeneweiss, D.F., "Prevention and treatment of construction damage", Journal of Arborculture 8:169 ^ Mountfort, Paul Rhys (2003). Nordic runes: understanding, casting, and interpreting the ancient Viking oracle. Inner Traditions / Bear & Company. p. 279. ISBN 9780892810932. ^ a b "Jonathan Drori on what we think we know | Video on". Ted.com. Retrieved 2010-10-18. ^ "Protecting Existing Trees on Building Sites" p.4 published by the City of Raleigh, North Carolina, March 1989, Reprinted February 2000 Species From Wikipedia, the free encyclopedia For other uses, see Species (disambiguation). The hierarchy of biological classification's eight major taxonomic ranks, which is an example of definition by genus and differentia. A genus contains one or more species. Intermediate minor rankings are not shown. In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are often used, such as similarity of DNA, morphology or ecological niche. Presence of specific locally adapted traits may further subdivide species into subspecies. The commonly used names for plant and animal taxa sometimes correspond to species: for example, "lion," "walrus," and "Camphor tree" – each refers to a species. In other cases common names do not: for example, "deer" refers to a family of 34 species, including Eld's Deer, Red Deer and Elk (Wapiti). The last two species were once considered a single species, illustrating how species boundaries may change with increased scientific knowledge. Each species is placed within a single genus. This is a hypothesis that the species is more closely related to other species within its genus than to species of other genera. All species are given a binomial name consisting of the generic name and specific name (or specific epithet). For example, Boa constrictor, which is commonly called by its bionomial name, and is one of five species of the Boa genus. A usable definition of the word "species" and reliable methods of identifying particular species are essential for stating and testing biological theories and for measuring biodiversity. Traditionally, multiple examples of a proposed species must be studied for unifying characters before it can be regarded as a species. Extinct species known only from fossils are generally difficult to give precise taxonomic rankings to. Because of the difficulties with both defining and tallying the total numbers of different species in the world, it is estimated that there are anywhere between 2 and 100 million different species.[1] Contents [hide] 1 Biologists' working definition 1.1 Common names and species 1.2 Placement within generation 1.3 Abbreviated names 2 Difficulty of defining "species" and identifying particular species 3 Definitions of species 4 Numbers of species 5 Importance in biological classification 6 Implications of assignment of species status 7 Historical development of the species concept 8 Species as taxa 9 See also 10 Notes and references 11 External links [edit]Biologists' working definition A usable definition of the word "species" and reliable methods of identifying particular species is essential for stating and testing biological theories and for measuring biodiversity. Traditionally, multiple examples of a proposed species must be studied for unifying characters before it can be regarded as a species. It is generally difficult to give precise taxonomic rankings to extinct species known only from fossils. Some biologists may view species as statistical phenomena, as opposed to the traditional idea, with a species seen as a class of organisms. In that case, a species is defined as a separately evolving lineage that forms a single gene pool. Although properties such as DNA-sequences and morphology are used to help separate closely related lineages, this definition has fuzzy boundaries.[2] However, the exact definition of the term "species" is still controversial, particularly in prokaryotes,[3] and this is called the species problem.[4] Biologists have proposed a range of more precise definitions, but the definition used is a pragmatic choice that depends on the particularities of the species of concern.[4] [edit]Common names and species The commonly used names for plant and animal taxa sometimes correspond to species: for example, "lion", "walrus", and "Camphor tree" – each refers to a species. In other cases common names do not: for example, "deer" refers to a family of 34 species, including Eld's Deer, Red Deer and Elk (Wapiti). The last two species were once considered a single species, illustrating how species boundaries may change with increased scientific knowledge. Because of the difficulties with both defining and tallying the total numbers of different species in the world, it is estimated that there are anywhere between 2 and 100 million different species.[1] [edit]Placement within generation Ideally, a species is given a formal, scientific name, although in practice there are very many unnamed species (which have only been described, not named). When a species is named, it is placed within a genus. From a scientific point of view this can be regarded as a hypothesis that the species is more closely related to other species within its genus (if any) than to species of other genera. Species and genus are usually defined as part of a larger taxonomic hierarchy. The best-known taxonomic ranks are, in order: life, domain, kingdom, phylum, class, order, family, genus, and species. This assignment to a genus is not immutable; later a different (or the same) taxonomist may assign it to a different genus, in which case the name will also change. In biological nomenclature, the name for a species is a two-part name (a binomial name), treated as Latin, although roots from any language can be used as well as names of locales or individuals. The generic name is listed first (with its leading letter capitalized), followed by a second term, the specific name (or specific epithet). For example, the species commonly known as the Longleaf Pine is Pinus palustris; gray wolves belong to the species Canis lupus, coyotes to Canis latrans, golden jackals to Canis aureus, etc., and all of those belong to the genus Canis (which also contains many other species). The name of the species is the whole binomial, not just the second term (which may be called the specific name for animals). This binomial naming convention, later formalized in the biological codes of nomenclature, was first used by Leonhart Fuchs and introduced as the standard by Carolus Linnaeus in his 1753, Species Plantarum (followed by his, 1758 Systema Naturae, 10th edition). At that time, the chief biological theory was that species represented independent acts of creation by God and were therefore considered objectively real and immutable, so the hypothesis of common descent did not apply. [edit]Abbreviated names Books and articles sometimes intentionally do not identify species fully and use the abbreviation "sp." in the singular or "spp." in the plural in place of the specific epithet: for example, Canis sp. This commonly occurs in the following types of situations: The authors are confident that some individuals belong to a particular genus but are not sure to which exact species they belong. This is particularly common in paleontology. The authors use "spp." as a short way of saying that something applies to many species within a genus, but do not wish to say that it applies to all species within that genus. If scientists mean that something applies to all species within a genus, they use the genus name without the specific epithet. In books and articles, genus and species names are usually printed in italics. If using "sp." and "spp.", these should not be italicized. [edit]Difficulty of defining "species" and identifying particular species Main article: Species problem The Greenish Warbler demonstrates the concept of a ring species. It is surprisingly difficult to define the word "species" in a way that applies to all naturally occurring organisms, and the debate among biologists about how to define "species" and how to identify actual species is called the species problem. Over two dozen distinct definitions of "species" are in use amongst biologists.[5] Most textbooks follow Ernst Mayr's definition of a species as "groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups".[4] Various parts of this definition serve to exclude some unusual or artificial matings: Those that occur only in captivity (when the animal's normal mating partners may not be available) or as a result of deliberate human action Animals that may be physically and physiologically capable of mating but, for various reasons, do not normally do so in the wild The typical textbook definition above works well for most multi-celled organisms, but there are several types of situations in which it breaks down: By definition it applies only to organisms that reproduce sexually. So it does not work for asexually reproducing single-celled organisms and for the relatively few parthenogenetic multi-celled organisms. The term "phylotype" is often applied to such organisms. Biologists frequently do not know whether two morphologically similar groups of organisms are "potentially" capable of interbreeding. There is considerable variation in the degree to which hybridization may succeed under natural conditions, or even in the degree to which some organisms use sexual reproduction between individuals to breed. In ring species, members of adjacent populations interbreed successfully but members of some non-adjacent populations do not. In a few cases it may be physically impossible for animals that are members of the same species to mate. However, these are cases in which human intervention has caused gross morphological changes, and are therefore excluded by the biological species concept. Horizontal gene transfer makes it even more difficult to define the word "species". There is strong evidence of horizontal gene transfer between very dissimilar groups of prokaryotes, and at least occasionally between dissimilar groups of eukaryotes; and Williamson[6] argues that there is evidence for it in some crustaceans and echinoderms. All definitions of the word "species" assume that an organism gets all its genes from one or two parents that are very like that organism, but horizontal gene transfer makes that assumption false. [edit]Definitions of species See also: Species problem The question of how best to define "species" is one that has occupied biologists for centuries, and the debate itself has become known as the species problem. Darwin wrote in chapter II of On the Origin of Species: No one definition has satisfied all naturalists; yet every naturalist knows vaguely what he means when he speaks of a species. Generally the term includes the unknown element of a distinct act of creation.[7] But later, in The Descent of Man, when addressing "The question whether mankind consists of one or several species", Darwin revised his opinion to say: it is a hopeless endeavour to decide this point on sound grounds, until some definition of the term "species" is generally accepted; and the definition must not include an element that cannot possibly be ascertained, such as an act of creation.[8] The modern theory of evolution depends on a fundamental redefinition of "species". Prior to Darwin, naturalists viewed species as ideal or general types, which could be exemplified by an ideal specimen bearing all the traits general to the species. Darwin's theories shifted attention from uniformity to variation and from the general to the particular. According to intellectual historian Louis Menand, Once our attention is redirected to the individual, we need another way of making generalizations. We are no longer interested in the conformity of an individual to an ideal type; we are now interested in the relation of an individual to the other individuals with which it interacts. To generalize about groups of interacting individuals, we need to drop the language of types and essences, which is prescriptive (telling us what finches should be), and adopt the language of statistics and probability, which is predictive (telling us what the average finch, under specified conditions, is likely to do). Relations will be more important than categories; functions, which are variable, will be more important than purposes; transitions will be more important than boundaries; sequences will be more important than hierarchies. This shift results in a new approach to "species"; Darwin concluded that species are what they appear to be: ideas, which are provisionally useful for naming groups of interacting individuals. "I look at the term species", he wrote, "as one arbitrarily given for the sake of convenience to a set of individuals closely resembling each other ... It does not essentially differ from the word variety, which is given to less distinct and more fluctuating forms. The term variety, again, in comparison with mere individual differences, is also applied arbitrarily, and for convenience sake." [9] Practically, biologists define species as populations of organisms that have a high level of genetic similarity. This may reflect an adaptation to the same niche, and the transfer of genetic material from one individual to others, through a variety of possible means. The exact level of similarity used in such a definition is arbitrary, but this is the most common definition used for organisms that reproduce asexually (asexual reproduction), such as some plants and microorganisms. This lack of any clear species concept in microbiology has led to some authors arguing that the term "species" is not useful when studying bacterial evolution. Instead they see genes as moving freely between even distantly related bacteria, with the entire bacterial domain being a single gene pool. Nevertheless, a kind of rule of thumb has been established, saying that species of Bacteria or Archaea with 16S rRNA gene sequences more similar than 97% to each other need to be checked by DNA-DNA Hybridization if they belong to the same species or not.[10] This concept has been updated recently, saying that the border of 97% was too low and can be raised to 98.7%.[11] In the study of sexually reproducing organisms, where genetic material is shared through the process of reproduction, the ability of two organisms to interbreed and produce fertile offspring of both sexes is generally accepted as a simple indicator that the organisms share enough genes to be considered members of the same species. Thus a "species" is a group of interbreeding organisms. This definition can be extended to say that a species is a group of organisms that could potentially interbreed – fish could still be classed as the same species even if they live in different lakes, as long as they could still interbreed were they ever to come into contact with each other. On the other hand, there are many examples of series of three or more distinct populations, where individuals of the population in the middle can interbreed with the populations to either side, but individuals of the populations on either side cannot interbreed. Thus, one could argue that these populations constitute a single species, or two distinct species. This is not a paradox; it is evidence that species are defined by gene frequencies, and thus have fuzzy boundaries. Consequently, any single, universal definition of "species" is necessarily arbitrary. Instead, biologists have proposed a range of definitions; which definition a biologists uses is a pragmatic choice, depending on the particularities of that biologist's research. Typological species A group of organisms in which individuals are members of the species if they sufficiently conform to certain fixed properties or "rights of passage". The clusters of variations or phenotypes within specimens (i.e. longer or shorter tails) would differentiate the species. This method was used as a "classical" method of determining species, such as with Linnaeus early in evolutionary theory. However, we now know that different phenotypes do not always constitute different species (e.g.: a 4-winged Drosophila born to a 2-winged mother is not a different species). Species named in this manner are called morphospecies[12] Morphological species A population or group of populations that differs morphologically from other populations. For example, we can distinguish between a chicken and a duck because they have different shaped bills and the duck has webbed feet. Species have been defined in this way since well before the beginning of recorded history. This species concept is highly criticized because more recent genetic data reveal that genetically distinct populations may look very similar and, contrarily, large morphological differences sometimes exist between very closely related populations. Nonetheless, most species known have been described solely from morphology. Biological / Isolation species A set of actually or potentially interbreeding populations. This is generally a useful formulation for scientists working with living examples of the higher taxa like mammals, fish, and birds, but more problematic for organisms that do not reproduce sexually. The results of breeding experiments done in artificial conditions may or may not reflect what would happen if the same organisms encountered each other in the wild, making it difficult to gauge whether or not the results of such experiments are meaningful in reference to natural populations. Biological / reproductive species Two organisms that are able to reproduce naturally to produce fertile offspring of both sexes. Organisms that can reproduce but almost always make infertile hybrids of at least one sex, such as a mule, hinny or F1 male cattalo are not considered to be the same species. Recognition species Based on shared reproductive systems, including mating behavior. The Recognition concept of species has been introduced by Hugh E. H. Paterson. Mate-recognition species A group of organisms that are known to recognize one another as potential mates. Like the isolation species concept above, it applies only to organisms that reproduce sexually. Unlike the isolation species concept, it focuses specifically on pre-mating reproductive isolation. Evolutionary / Darwinian species A group of organisms that shares an ancestor; a lineage that maintains its integrity with respect to other lineages through both time and space. At some point in the progress of such a group, some members may diverge from the main population and evolve into a subspecies, a process that eventually will lead to the formation of a new full species if isolation (geographical or ecological) is maintained. Phylogenetic (Cladistic)[verification needed] A group of organisms that shares an ancestor; a lineage that maintains its integrity with respect to other lineages through both time and space. At some point in the progress of such a group, members may diverge from one another: when such a divergence becomes sufficiently clear, the two populations are regarded as separate species. This differs from evolutionary species in that the parent species goes extinct taxonomically when a new species evolve, the mother and daughter populations now forming two new species. Subspecies as such are not recognized under this approach; either a population is a phylogenetic species or it is not taxonomically distinguishable. Ecological species A set of organisms adapted to a particular set of resources, called a niche, in the environment. According to this concept, populations form the discrete phonetic clusters that we recognize as species because the ecological and evolutionary processes controlling how resources are divided up tend to produce those clusters. Genetic species Based on similarity of DNA of individuals or populations. Techniques to compare similarity of DNA include DNA-DNA hybridization, and genetic fingerprinting (or DNA barcoding). Phenetic species Based on phenotypes.[verification needed] Microspecies Species that reproduce without meiosis or fertilization so that each generation is genetically identical to the previous generation. See also apomixis. Cohesion species Most inclusive population of individuals having the potential for phenotypic cohesion through intrinsic cohesion mechanisms. This is an expansion of the mate-recognition species concept to allow for post-mating isolation mechanisms; no matter whether populations can hybridize successfully, they are still distinct cohesion species if the amount of hybridization is insufficient to completely mix their respective gene pools. Evolutionarily Significant Unit (ESU) An evolutionarily significant unit is a population of organisms that is considered distinct for purposes of conservation. Often referred to as a species or a wildlife species, an ESU also has several possible definitions, which coincide with definitions of species. In practice, these definitions often coincide, and the differences between them are more a matter of emphasis than of outright contradiction. Nevertheless, no species concept yet proposed is entirely objective, or can be applied in all cases without resorting to judgment. Given the complexity of life, some have argued that such an objective definition is in all likelihood impossible, and biologists should settle for the most practical definition. For most vertebrates, this is the biological species concept (BSC), and to a lesser extent (or for different purposes) the phylogenetic species concept (PSC). Many BSC subspecies are considered species under the PSC; the difference between the BSC and the PSC can be summed up insofar as that the BSC defines a species as a consequence of manifest evolutionary history, while the PSC defines a species as a consequence of manifest evolutionary potential. Thus, a PSC species is "made" as soon as an evolutionary lineage has started to separate, while a BSC species starts to exist only when the lineage separation is complete. Accordingly, there can be considerable conflict between alternative classifications based upon the PSC versus BSC, as they differ completely in their treatment of taxa that would be considered subspecies under the latter model (e.g., the numerous subspecies of honey bees). [edit]Numbers of species Undiscovered and discovered species[verification needed][citation needed] Bearing in mind the aforementioned problems with categorising species, the following numbers are only a soft guide. In 2007, they broke down as follows:[13] Total number of species (estimated): 7–100 millions (identified and unidentified), including: 5–10 million bacteria;[14] 74,000–120,000 fungi;[15] Of the identified eukaryote species we have:[13] 1.6 million, including: 297,326 plants, including: 15,000 mosses, 13,025 Ferns and horsetails, 980 gymnosperms, 258,650 angiosperms, 199,350 dicotyledons, 59,300 monocotyledons, 9,671 Red and green algae, 28,849 fungi & other non-animals, including: 10,000 lichens, 16,000 mushrooms, 2,849 brown algae, 1,250,000 animals, including: 1,203,375 invertebrates: 950,000 insects, 81,000 mollusks, 40,000 crustaceans, 2,175 corals, 130,200 others; 59,811 vertebrates: 29,300 fish, 6,199 amphibians, 8,240 reptiles, 9,956 birds, 5,416 mammals At present, organisations such as the Global Taxonomy Initiative, the European Distributed Institute of Taxonomy and the Census of Marine Life[16] (the latter only for marine organisms) are trying to improve taxonomy and implement previously undiscovered species to the taxonomy system. Because we know but a portion of the organisms in the biosphere, we do not have a complete understanding of the workings of our environment. To make matters worse, despite the discovery of new species, according to professor James Mallet, we are wiping out these species at an unprecedented rate.[17] This means that even before a new species has had the chance of being studied and classified, it may already be extinct. [edit]Importance in biological classification The idea of species has a long history. It is one of the most important levels of classification, for several reasons: It often corresponds to what lay people treat as the different basic kinds of organism – dogs are one species, cats another. It is the standard binomial nomenclature (or trinomial nomenclature) by which scientists typically refer to organisms. It is the highest taxonomic level that cannot be made more or less inclusionary. After years of use, the concept remains central to biology and a host of related fields, and yet also remains at times ill-defined. [edit]Implications of assignment of species status The naming of a particular species may be regarded as a hypothesis about the evolutionary relationships and distinguishability of that group of organisms. As further information comes to hand, the hypothesis may be confirmed or refuted. Sometimes, especially in the past when communication was more difficult, taxonomists working in isolation have given two distinct names to individual organisms later identified as the same species. When two named species are discovered to be of the same species, the older species name is usually retained, and the newer species name dropped, a process called synonymization, or colloquially, as lumping. Dividing a taxon into multiple, often new, taxons is called splitting. Taxonomists are often referred to as "lumpers" or "splitters" by their colleagues, depending on their personal approach to recognizing differences or commonalities between organisms (see lumpers and splitters). Traditionally, researchers relied on observations of anatomical differences, and on observations of whether different populations were able to interbreed successfully, to distinguish species; both anatomy and breeding behavior are still important to assigning species status. As a result of the revolutionary (and still ongoing) advance in microbiological research techniques, including DNA analysis, in the last few decades, a great deal of additional knowledge about the differences and similarities between species has become available. Many populations formerly regarded as separate species are now considered a single taxon, and many formerly grouped populations have been split. Any taxonomic level (species, genus, family, etc.) can be synonymized or split, and at higher taxonomic levels, these revisions have been still more profound. From a taxonomical point of view, groups within a species can be defined as being of a taxon hierarchically lower than a species. In zoology only the subspecies is used, while in botany the variety, subvariety, and form are used as well. In conservation biology, the concept of evolutionary significant units (ESU) is used, which may be define either species or smaller distinct population segments. Identifying and naming species is the providence of alpha taxonomy. [edit]Historical development of the species concept The following text needs to be harmonized with text in Species problem. This section does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (September 2009) Linnaeus believed in the fixity of species. In the earliest works of science, a species was simply an individual organism that represented a group of similar or nearly identical organisms. No other relationships beyond that group were implied. Aristotle used the words genus and species to mean generic and specific categories. Aristotle and other pre-Darwinian scientists took the species to be distinct and unchanging, with an "essence", like the chemical elements. When early observers began to develop systems of organization for living things, they began to place formerly isolated species into a context. Many of these early delineation schemes would now be considered whimsical and these included consanguinity based on color (all plants with yellow flowers) or behavior (snakes, scorpions and certain biting ants). In the 18th century Swedish scientist Carolus Linnaeus classified organisms according to differences in the form of reproductive apparatus. Although his system of classification sorts organisms according to degrees of similarity, it made no claims about the relationship between similar species. At that time, it was still widely believed that there was no organic connection between species, no matter how similar they appeared. This approach also suggested a type of idealism: the notion that each species existed as an "ideal form". Although there are always differences (although sometimes minute) between individual organisms, Linnaeus considered such variation problematic. He strove to identify individual organisms that were exemplary of the species, and considered other non-exemplary organisms to be deviant and imperfect. By the 19th century most naturalists understood that species could change form over time, and that the history of the planet provided enough time for major changes. Jean-Baptiste Lamarck, in his 1809 Zoological Philosophy, offered one of the first logical arguments against creationism. The new emphasis was on determining how a species could change over time. Lamarck suggested that an organism could pass on an acquired trait to its offspring, i.e., the giraffe's long neck was attributed to generations of giraffes stretching to reach the leaves of higher treetops (this well-known and simplistic example, however, does not do justice to the breadth and subtlety of Lamarck's ideas). With the acceptance of the natural selection idea of Charles Darwin in the 1860s, however, Lamarck's view of goal-oriented evolution, also known as a teleological process, was eclipsed. Recent interest in inheritance of acquired characteristics centers around epigenetic processes, e.g. methylation, that do not affect DNA sequences, but instead alter expression in an inheritable manner. Thus, neo-lamarckism, as it is sometimes termed, is not a challenge to the theory of evolution by natural selection. Charles Darwin and Alfred Wallace provided what scientists now consider as the most powerful and compelling theory of evolution. Darwin argued that it was populations that evolved, not individuals. His argument relied on a radical shift in perspective from that of Linnaeus: rather than defining species in ideal terms (and searching for an ideal representative and rejecting deviations), Darwin considered variation among individuals to be natural. He further argued that variation, far from being problematic, actually provides the explanation for the existence of distinct species. Darwin's work drew on Thomas Malthus' insight that the rate of growth of a biological population will always outpace the rate of growth of the resources in the environment, such as the food supply. As a result, Darwin argued, not all the members of a population will be able to survive and reproduce. Those that did will, on average, be the ones possessing variations—however slight—that make them slightly better adapted to the environment. If these variable traits are heritable, then the offspring of the survivors will also possess them. Thus, over many generations, adaptive variations will accumulate in the population, while counter-adaptive traits will tend to be eliminated. It should be emphasized that whether a variation is adaptive or non-adaptive depends on the environment: different environments favor different traits. Since the environment effectively selects which organisms live to reproduce, it is the environment (the "fight for existence") that selects the traits to be passed on. This is the theory of evolution by natural selection. In this model, the length of a giraffe's neck would be explained by positing that proto-giraffes with longer necks would have had a significant reproductive advantage to those with shorter necks. Over many generations, the entire population would be a species of long-necked animals. In 1859, when Darwin published his theory of natural selection, the mechanism behind the inheritance of individual traits was unknown. Although Darwin made some speculations on how traits are inherited (pangenesis), his theory relies only on the fact that inheritable traits exist, and are variable (which makes his accomplishment even more remarkable.) Although Gregor Mendel's paper on genetics was published in 1866, its significance was not recognized. It was not until 1900 that his work was rediscovered by Hugo de Vries, Carl Correns and Erich von Tschermak, who realised that the "inheritable traits" in Darwin's theory are genes. The theory of the evolution of species through natural selection has two important implications for discussions of species—consequences that fundamentally challenge the assumptions behind Linnaeus' taxonomy. First, it suggests that species are not just similar, they may actually be related. Some students of Darwin argue that all species are descended from a common ancestor. Second, it supposes that "species" are not homogeneous, fixed, permanent things; members of a species are all different, and over time species change. This suggests that species do not have any clear boundaries but are rather momentary statistical effects of constantly changing gene-frequencies. One may still use Linnaeus' taxonomy to identify individual plants and animals, but one can no longer think of species as independent and immutable. The rise of a new species from a parental line is called speciation. There is no clear line demarcating the ancestral species from the descendant species. Although the current scientific understanding of species suggests that there is no rigorous and comprehensive way to distinguish between different species in all cases, biologists continue to seek concrete ways to operationalize the idea. One of the most popular biological definitions of species is in terms of reproductive isolation; if two creatures cannot reproduce to produce fertile offspring of both sexes, then they are in different species. This definition captures a number of intuitive species boundaries, but it remains imperfect. It has nothing to say about species that reproduce asexually, for example, and it is very difficult to apply to extinct species. Moreover, boundaries between species are often fuzzy: there are examples where members of one population can produce fertile offspring of both sexes with a second population, and members of the second population can produce fertile offspring of both sexes with members of a third population, but members of the first and third population cannot produce fertile offspring, or can only produce fertile offspring of the homozygous sex. Consequently, some people reject this definition of a species. Richard Dawkins defines two organisms as conspecific if and only if they have the same number of chromosomes and, for each chromosome, both organisms have the same number of nucleotides (The Blind Watchmaker, p. 118). However, most if not all taxonomists would strongly disagree[citation needed]. For example, in many amphibians, most notably in New Zealand's Leiopelma frogs, the genome consists of "core" chromosomes that are mostly invariable and accessory chromosomes, of which exist a number of possible combinations. Even though the chromosome numbers are highly variable between populations, these can interbreed successfully and form a single evolutionary unit. In plants, polyploidy is extremely commonplace with few restrictions on interbreeding; as individuals with an odd number of chromosome sets are usually sterile, depending on the actual number of chromosome sets present, this results in the odd situation where some individuals of the same evolutionary unit can interbreed with certain others and some cannot, with all populations being eventually linked as to form a common gene pool. The classification of species has been profoundly affected by technological advances that have allowed researchers to determine relatedness based on molecular markers, starting with the comparatively crude blood plasma precipitation assays in the mid-20th century to Charles Sibley's ground-breaking DNA-DNA hybridization studies in the 1970s leading to DNA sequencing techniques. The results of these techniques caused revolutionary changes in the higher taxonomic categories (such as phyla and classes), resulting in the reordering of many branches of the phylogenetic tree (see also: molecular phylogeny). For taxonomic categories below genera, the results have been mixed so far; the pace of evolutionary change on the molecular level is rather slow, yielding clear differences only after considerable periods of reproductive separation. DNA-DNA hybridization results have led to misleading conclusions, the Pomarine Skua – Great Skua phenomenon being a famous example. Turtles have been determined to evolve with just one-eighth of the speed of other reptiles on the molecular level, and the rate of molecular evolution in albatrosses is half of what is found in the rather closely related storm-petrels. The hybridization technique is now obsolete and is replaced by more reliable computational approaches for sequence comparison. Molecular taxonomy is not directly based on the evolutionary processes, but rather on the overall change brought upon by these processes. The processes that lead to the generation and maintenance of variation such as mutation, crossover and selection are not uniform (see also molecular clock). DNA is only extremely rarely a direct target of natural selection rather than changes in the DNA sequence enduring over generations being a result of the latter; for example, silent transition-transversion combinations would alter the melting point of the DNA sequence, but not the sequence of the encoded proteins and thus are a possible example where, for example in microorganisms, a mutation confers a change in fitness all by itself. [edit]Species as taxa The scientific name of a species (often of Latin or Greek origin) in the binominal nomenclature introduced by Carl Linnaeus in 1753 is composed of two parts, which are written in italic font and for which there are different expressions in botany and zoology. The first part of that name is spelled upper case and is in both disciplines known as the genus name (also called the generic name). The second part is always spelled lower case and in botany it is called the specific epithet. Example: in the European beech (Fagus sylvatica) the component Fagus refers to the genus, sylvatica is the specific epithet. In zoology, the second part is called the specific name. Example: in the lion (Panthera leo) the component Panthera refers to the genus, leo is the specific name. The scientific name is completed when authors, years and parentheses are added. In botany the name of the author is usually abbreviated, for example "L." stands for "Linnaeus". Example: shiitake Lentinula edodes (Berk.) Pegler M. J. Berkeley was the first to describe the species, D. Pegler has placed it into the currently used system. In zoology, the addition of author and year are optional, Panthera leo is thus an entirely correct name. The International Code of Zoological Nomenclature prescribes how to add author(s) (if possible not abbreviated) and year (or author alone without year). If the species is cited in different genus than the one in which it was originally described, author(s) and year are given in parentheses. Between author and year often a comma is set (but not required). Example: lion Panthera leo (Linnaeus, 1758) Carl Nilsson Linnæus described the lion first and as Felis leo. The person who first placed the lion in the genus Panthera Oken, 1816 is not relevant in zoology. Instead of Linnæus, usually Linnaeus is spelled. [edit]See also Cline Cryptic species complex Encyclopedia of Life Endangered species Genetic pollution Genetic erosion Ring species Species problem Systematics [edit]Notes and references ^ a b "Just How Many Species Are There, Anyway?". 2003-05-26. Retrieved 2008-01-15 ^ De Queiroz K (December 2007). "Species concepts and species delimitation". Syst. Biol. 56 (6): 879–86. doi:10.1080/10635150701701083. PMID 18027281. ^ Fraser C, Alm EJ, Polz MF, Spratt BG, Hanage WP (February 2009). "The bacterial species challenge: making sense of genetic and ecological diversity". Science (journal) 323 (5915): 741–6. doi:10.1126/science.1159388. PMID 19197054. ^ a b c de Queiroz K (May 2005). "Ernst Mayr and the modern concept of species". Proc. Natl. Acad. Sci. U.S.A. 102 Suppl 1: 6600–7. doi:10.1073/pnas.0502030102. PMID 15851674. PMC 1131873. ^ Wilkins, John (2010-10-20). "How many species concepts are there?". The Guardian. Retrieved 2010-10-19. ^ David I. Williamson (2003). The Origins of Larvae. Kluwer. ISBN 1-4020-1514-3. ^ Darwin 1859 p.59 ^ Darwin 1871 p. 24 ^ Louis Menand (2001) The Metaphysical Club New York: Farrar, Straus and Giroux 123–124 ^ Stackebrandt E, Goebel BM (1994). "Taxonomic note: a place for DNA-DNA reassociation and 16S rRNA sequence analysis in the present species definition in bacteriology". Int. J. Syst. Bacteriol. 44: 846–9. doi:10.1099/00207713-44-4-846. ^ Stackebrandt E, Ebers J (2006). "Taxonomic parameters revisited: tarnished gold standards". Microbiol. Today 33: 152–5. ^ Michael Ruse (August 1969). "Definitions of Species in Biology". The British Journal for the Philosophy of Science (Oxford University Press) 20 (2): 97–119. doi:10.1093/bjps/20.2.97. ^ a b "Number of Species on Earth". Current Results. 2007-01-01. Retrieved 2010-04-23. ^ Sogin ML, Morrison HG, Huber JA, et al. (August 2006). "Microbial diversity in the deep sea and the underexplored "rare biosphere"". Proc. Natl. Acad. Sci. U.S.A. 103 (32): 12115–20. doi:10.1073/pnas.0605127103. PMID 16880384. PMC 1524930. Cheung L (Monday, 31 July 200). "Thousands of microbes in one gulp". BBC. ^ David L. Hawksworth (2001). "The magnitude of fungal diversity: the 1•5 million species estimate revisited". Mycological Research 105 (12): 1422–1432. doi:10.1017/S0953756201004725. ^ "Census of marine life". Coml.org. Retrieved 2010-04-23. ^ Robin McKie and Zoe Corbyn (2005-09-25). "Discovery of new species and extermination at high rate". London: Guardian. Retrieved 2010-04-23. Family (biology) From Wikipedia, the free encyclopedia "Subfamily" redirects here. For the protein classification, see Protein subfamily. The hierarchy of biological classification's eight major taxonomic ranks, which is an example of definition by genus and differentia. An order contains one or more families. Intermediate minor rankings are not shown. In biological classification, family (Latin: familia) is a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the prefix sub-: subfamily (Latin: subfamilia). a taxonomic unit, a taxon, in that rank. In that case the plural is families (Latin familiae) Example: Walnuts and hickories belong to the Juglandaceae, or walnut family. What does and does not belong to each family is determined by a taxonomist. Similarly for the question if a particular family should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing a family. Some taxa are accepted almost universally, while others are recognised only rarely. Contents [hide] 1 History of the concept 2 Uses 3 See also 4 References [edit]History of the concept Family, as a rank intermediate between order and genus, is a relatively recent invention. The taxonomic term familia was first used by French botanist Pierre Magnol in his Prodromus historiae generalis plantarum, in quo familiae plantarum per tabulas disponuntur (1689) where he called the seventy-six groups of plants he recognised in his tables families (familiae). The concept of rank at that time was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera, which is far from how the term is used today. Carolus Linnaeus used the word familia in his Philosophia botanica (1751) to denote major groups of plants: trees, herbs, ferns, palms, and so on. He used this term only in the morphological section of the book, discussing the vegetative and generative organs of plants. Subsequently, in French botanical publications, from Michel Adanson's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille was used as a French equivalent of the Latin ordo (or ordo naturalis). In nineteenth century works such as the Prodromus of Augustin Pyramus de Candolle and the Genera Plantarum of George Bentham and Joseph Dalton Hooker this word ordo was used for what now is given the rank of family. In zoology, the family as a rank intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes, disposés dans un ordre naturel (1796). He used families (some of them not named) in some but not in all his orders of "insects" (which then included all arthropods). Since the beginning of the 20th century, however, the term has been consistently used in its modern sense. Its usage and characteristic ending of the names belonging to this category are governed by the various nomenclature codes. These are "-idae" in the zoological code,[1] and "-aceae" in the botanical[2] and bacteriological codes.[3] [edit]Uses Families may be used for evolutionary and palaeontological studies because they are more stable then lower taxonomic levels such as genera and species.[4][5] [edit]See also Systematics, the study of the diversity of life Cladistics, the classification of organisms by their order of branching in an evolutionary tree Phylogenetics, the study of evolutionary relatedness among various groups of organisms Taxonomy Virus classification List of Anuran families List of Testudines families List of fish families List of families of spiders Perennial plant From Wikipedia, the free encyclopedia (Redirected from Perennial) "Perennial" redirects here. For other uses, see Perennial (disambiguation). Flower of common chicory, a perennial plant A perennial plant or simply perennial (Latin per, "through", annus, "year") is a plant that lives for more than two years.[1] The term is often used to differentiate a plant from shorter lived annuals and biennials. When used by gardeners or horticulturalists, perennial applies specifically to winter hardy herbaceous plants. Scientifically, woody plants like shrubs and trees are also perennial in their habit. Perennials, especially small flowering plants, grow and bloom over the spring and summer and then die back every autumn and winter, then return in the spring from their root-stock rather than seeding themselves as an annual plant does. These are known as herbaceous perennials. However, depending on the rigors of local climate, a plant that is a perennial in its native habitat, or in a milder garden, may be treated by a gardener as an annual and planted out every year, from seed, from cuttings or from divisions. The symbol for a perennial plant, based on Species Plantarum by Linnaeus, is , which is also the astronomical symbol for the planet Jupiter.[2] Contents [hide] 1 Life cycle 2 Structure 3 Growth 4 Benefits in agriculture 5 Location 6 Types 7 Perennial fruits 8 Perennial herbs 9 Perennial vegetables 10 See also 11 References 12 External links [edit]Life cycle Perennial plants can be short-lived (only a few years) or they can be long-lived, as are some woody plants like trees which can live for over 4,000 years. They can vary in height from only a few millimeters to over 100 meters tall. They include a wide assortment of plant groups from ferns and liverworts to the highly diverse flowering plants like orchids and grasses. Plants that flower and fruit only once and then die are termed monocarpic or semelparous. However, most perennials are polycarpic, flowering over many seasons in their lifetime. [edit]Structure Perennials typically grow structures that allow them to adapt to living from one year to the next through a form of vegetative reproduction rather than seeding. These structures include bulbs, tubers, woody crowns, rhizomes plus others. They might have specialized stems or crowns that allow them to survive periods of dormancy over cold or dry seasons during the year. Annuals produce seeds to continue the species as a new generation while the growing season is suitable, and the seeds survive over the cold or dry period to begin growth when the conditions are again suitable. Many perennials, in contrast, have specialized to survive under extreme environmental conditions: some have adapted to survive hot and dry conditions, or to survive under cold temperatures. Those plants tend to invest a lot of resource into their adaptations and often do not flower and set seed until after a few years of growth. Many perennials produce relatively large seeds, which can have an advantage, with larger seedlings produced after germination that can better compete with other plants or more quickly develop leaves for photosynthesis. Annuals tend to produce many more seeds per plant since they will die at the end of the growing season, while perennials are not under the same pressure to produce large numbers of seeds but can produce seeds over many years. The dahlia is a perennial. [edit]Growth In warmer and more favorable climates, perennials grow continuously. In seasonal climates, their growth is limited to the growing season. For example, in temperate regions a perennial plant may grow and bloom during the warm part of the year, with the foliage dying back in the winter. These plants are deciduous perennials. Regrowth is from existing stem tissue. In many parts of the world, seasonality is expressed as wet and dry periods rather than warm and cold periods. In some species, perennials retain their foliage all year round; these are evergreen perennials. With their roots protected below ground in the soil layer, perennial plants are notably tolerant of wildfire. Herbaceous perennials are also able to tolerate the extremes of cold in temperate and Arctic winters, with less sensitivity than trees or shrubs. Knowing the planting zone can be very useful when you are planning your garden and flower bed areas. Gardeners should compare their garden climates with the climate where a plant is known to grow well. Most plants are marked with a zone number which corresponds with a region on a map where that plant will survive. While a range of zones might be listed, the lower of the zone numbers indicates the lowest recommended zone in which that plant can survive. It is possible that a plant might thrive outside a labeled zone area. [edit]Benefits in agriculture Switchgrass is a deep-rooted perennial. These roots are more than 3 meters long. Although most of humanity is fed by seeds from annual grain crops, perennial crops provide numerous benefits.[3] Perennial plants often have deep, extensive root systems which can hold soil to prevent erosion, capture dissolved nitrogen before it can contaminate ground and surface water, and outcompete weeds (reducing the need for herbicides). These potential benefits of perennials have resulted in new attempts to increase the seed yield of perennial species[4], which could result in the creation of new perennial grain crops.[5] Some examples of new perennial crops being developed are perennial rice and intermediate wheatgrass. [edit]Location Perennial plants dominate many natural ecosystems on land and in fresh water, with only a very few (e.g. Zostera) occurring in shallow sea water. Herbaceous perennial plants are particularly dominant in conditions too fire-prone for trees and shrubs, e.g., most plants on prairies and steppes are perennials; they are also dominant on tundra too cold for tree growth. Nearly all forest plants are perennials, including the trees and shrubs. Perennial plants are usually better competitors than annual plants, especially under stable, resource-poor conditions. This is due to the development of larger root systems which can access water and soil nutrients deeper in the soil and to earlier emergence in the spring. [edit]Types Examples of evergreen perennials include Begonia and banana. Examples of deciduous perennials include goldenrod and mint. Examples of monocarpic perennials include Agave and some species of Streptocarpus. Examples of woody perennials include maple, pine, and apple trees. Examples of herbaceous perennials used in agriculture include alfalfa, Thinopyrum intermedium, and Red clover. [edit]Perennial fruits Apple Apricot Avocado Banana Blackcurrant Blueberry Currant Feijoa Grape Kiwi Fruit Japanese Wineberry Pear Persimmon Pineapple Plum Raspberries Strawberry Strawberry Tree [edit]Perennial herbs Agastache Alfalfa Basil, many varieties: African Blue, East Indian Chives Dill Fennel Ferula Garlic Ginger Hops -Humulus Horseradish Lavender Lemon Balm Cannabis Mint Onions, many varieties: Potato onions, Shallots, Egyptian onions, Japanese bunching onions, Welsh onions, Chinese leeks Oregano Piper nigrum (black pepper) Rosemary Sage Thyme Valerian White Horehound -Marrubium vulgare Yarrow (Achillea millefolium) [edit]Perennial vegetables Allium tricoccum: commonly known as ramps, spring onion, ramson, wild leek, or ail des bois Asparagus Broccoli: Nine Star chicory Chives Colocasia esculenta Eggplant Globe artichoke Ground Nut (Apios americana) Hog nut Jerusalem Artichoke konjac lamb's quarter leek Milkweed (Asclepias) Okra potato Radicchio or a.k.a. Italian Chicory Rhubarb shallot Siberian Pea Tree (Caragana arborescens) sorrel Rakkyo Sea Kale Spinach varieties: Ceylon Spinach, Sissoo Spinach, New Zealand Spinach Sweet potato Taro Watercress [edit]See also Annual plant Biennial plant Herbaceous Perennial grain [edit]References ^ The Garden Helper. The Difference Between Annual Plants and Perennial Plants in the Garden. Retrieved on 2008-06-22. ^ Stearn, William T. "Botanical Latin" (four editions, 1966-92) ^ Glover et al. Future Farming: A return to roots? Retrieved on 2008-11-11. ^ Moffat 1996 [1] Retrieved on 2008-11-14 ^ Cox et al. 2000 [2] Retrieved on 2008-11-14 [edit]External links USDA Plant Hardiness Zone Map Gardening with Perennials Edible Aroids Plants for a Future Tillage From Wikipedia, the free encyclopedia Cultivating after early rain. Tillage is the agricultural preparation of the soil by ploughing, ripping, or turning it. Tillage can also mean the land that is tilled. There are two types of tillage: primary and secondary tillage. Contents [hide] 1 Tillage systems 1.1 Intensive tillage 1.2 Reduced tillage 1.3 Conservation tillage 1.4 Purposes Of Tillage 1.5 General comments 2 Definitions 3 History of tilling 4 Alternatives to tilling 5 See also 6 References 6.1 Further information [edit]Tillage systems [edit]Intensive tillage Intensive tillage systems leave less than 15% crop residue cover less than 500 pounds per acre (560 kg/ha) of small grain residue. These types of tillage systems are often referred to as conventional tillage systems but as reduced and conservation tillage systems have been more widely adopted, it is often not appropriate to refer to this type of system as conventional. These systems involve often multiple operations with implements such as a mold board, disk, and/or chisel plow. Then a finisher with a harrow, rolling basket, and cutter can be used to prepare the seed bed. There are many variations. [edit]Reduced tillage Reduced tillage systems leave between 15 and 30% residue cover on the soil or 500 to 1000 pounds per acre (560 to 1100 kg/ha) of small grain residue during the critical erosion period. This may involve the use of a chisel plow, field cultivators, or other implements. See the general comments below to see how they can affect the amount of residue. [edit]Conservation tillage Conservation tillage systems are methods of soil tillage which leave a minimum of 30% of crop residue on the soil surface or at least 1,000 lb/ac (1,100 kg/ha) of small grain residue on the surface during the critical soil erosion period. This slows water movement, which reduces the amount of soil erosion. Conservation tillage systems also benefit farmers by reducing fuel consumption and soil compaction. By reducing the number of times the farmer travels over the field, farmers realize significant savings in fuel and labor. Conservation tillage was used on about 38%, 109,000,000 acres (440,000 km2), of all US cropland, 293,000,000 acres (1,190,000 km2) planted as of 2004 according to the USDA. However, conservation tillage systems delay warming of the soil due to the reduction of dark earth exposure to the warmth of the spring sun, thus delaying the planting of the next year's spring crop.[1] No-till Strip-Till Mulch-till Ridge-Till [edit]Purposes Of Tillage Positive effects Ploughing loosens and aerates the soil which can facilitate some deeper penetration of roots. Tillage is believed to help in the growth of microorganisms present in the soil and thus, though fertility decline as microorganisms' boom period after tilling is followed by a bust period. It is debatable whether worms benefit or suffer from tillage.[citation needed] It helps in the mixing of residue from the harvest, organic matter(humus) and nutrients evenly throughout the soil. It is used for destroying weeds. Negative effects of ploughing The soil looses a lot of its nutrients like carbon, nitrogen and its ability to store humidity. see No-till-farming Some compaction of the lower layers of soil[citation needed] Eutrophication Can attract some harmful insects to the field. [edit]General comments The type of implement makes the most difference, although other factors can have an effect.[2] Tilling in absolute darkness (night tillage) might reduce the number of weeds that sprout following the tilling operation by half. Light is necessary to break the dormancy of some weed species' seed, so if fewer seeds are exposed to light during the tilling process, fewer will sprout. This may help reduce the amount of herbicides needed for weed control.[3] Greater speeds, when using certain tillage implements (disks and chisel plows), lead to more intensive tillage (i.e., less residue is on the soil surface). Increasing the angle of disks causes residues to be buried more deeply. Increasing their concavity makes them more aggressive. Chisel plows can have spikes or sweeps. Spikes are more aggressive. Percentage residue is used to compare tillage systems because the amount of crop residue affects the soil loss due to erosion.[2][4] See Soybean management practices to see what types of tillage are currently recommended for Soybean Production. [edit]Definitions Primary tillage loosens the soil and mixes in fertilizer and/or plant material, resulting in soil with a rough texture. Secondary tillage produces finer soil and sometimes shapes the rows. It can be done by using various combinations of equipment:harrow, dibble, hoe, shovel, rotary tillers, subsoiler, ridge or bed forming tillers, roller. Weed plants (seeds, tubers, etc.) may be exhausted by repeated tilling. The weeds expend energy to reach the surface, and then get turned into the soil by tilling. The cycle is repeated until the weeds are dead. [edit]History of tilling Tilling was first performed via human labor, sometimes involving slaves. Hoofed animals could also be used to till soil via trampling. The wooden plow was then invented. It could be pulled by mule, ox, elephant, water buffalo, or similar sturdy animal. Horses are generally unsuitable, though breeds such as the scyne could work. The steel plow allowed farming in the American Midwest, where tough prairie grasses and rocks caused trouble. Soon after 1900, the farm tractor was introduced, which eventually made modern large-scale agriculture possible. [edit]Alternatives to tilling Modern agricultural science has greatly reduced the use of tillage. Crops can be grown for several years without any tillage through the use of herbicides to control weeds, crop varieties that tolerate packed soil, and equipment that can plant seeds or fumigate the soil without really digging it up. This practice, called no-till farming, reduces costs and environmental change by reducing soil erosion and diesel fuel usage (although it does require the use of herbicides). Most organic farming tends to require extensive tilling, as did most farming throughout history, although researchers are investigating farming in polyculture that would eliminate the need for both tillage and pesticides, such as no-dig gardening. [edit]See also Advance sowing Optimum water content for tillage SWEEP (Soil and Water Environmental Enhancement program) TERON (Tillage erosion) [edit]References Sprague, Milton A., and Glover B. Triplett. 1986. No-tillage and surface-tillage agriculture : the tillage revolution. New York, Wiley. ISBN 978-0-471-88410-1 Troeh, Frederick R., J. Arthur Hobbs, Roy L. Donahue. 1991. Soil and water conservation for productivity and environmental protection, 2nd ed. Englewood Cliffs, N.J., Prentice-Hall. ISBN 978-0130968074 Soil Science of America. 2009. Glossary of Soil Science Terms. [Online]. Available at https://www.soils.org/publications/soils-glossary (28 September 2009; verified 28 September 2009). Soil Science of America, Madison, WI. No-Plow Farmers Save Our Soil agriculture_sustainable_farming.html I will teach the world farming without oil ^ Strip Till for Field Crop Production ^ a b Conservation Tillage and Residue Management to Reduce Soil Erosion University of Missouri: Extension ^ http://www.ars.usda.gov/is/AR/archive/dec95/tilling1295.htm ^ Methods for measuring crop residue Integrated Crop Management, May 2002 [edit]Further information Brady, Nyle C.; R.R. Weil (2002). The nature and property of soils, 13th edition. New Jersey: Prentice Hall. ISBN 0-13-016763-0. Natural Resource Conservation Service Farm Bill Conservation Provisions Conservation Tillage Conservation Technology Information Centre Yusuf, Raji I.; Siemens, John C.; Bullock, Donald G. (November 1999). "Growth Analysis of Soybean under No-Tillage and Conventional Tillage Systems". Agronomy Journal (Madison, WI: American Society of Agronomy) 91: 928–933. ISSN 1435-0645. Retrieved October 2009.