Aesculus 474577 225284659 2008-07-12T21:53:14Z 70.241.65.109 /* Etymology */ 1rst -> 1st : ''For the South African Thoroughbred racehorse see: [[Horse Chestnut (horse)]].'' {{Taxobox | name = ''Aesculus'' - Buckeyes and Horse-chestnuts | image = Horse-chestnut 800.jpg | image_width = 300px | image_caption = ''Aesculus hippocastanum'' | regnum = [[Plant]]ae | divisio = [[flowering plant|Magnoliophyta]] | classis = [[dicotyledon|Magnoliopsida]] | ordo = [[Sapindales]] | familia = [[Sapindaceae]] | genus = '''''Aesculus''''' | genus_authority = [[Carolus Linnaeus|L.]] | subdivision_ranks = Species | subdivision = ''[[Aesculus arguta]]'': Texas buckeye<br/> ''[[Aesculus californica]]'': California buckeye<br/> ''[[Aesculus chinensis]]'': Chinese horse-chestnut<br/> ''[[Aesculus flava]]'' (''A. octandra''): yellow buckeye<br/> ''[[Aesculus glabra]]'': Ohio Buckeye<br/> ''[[Aesculus hippocastanum]]'': common horse-chestnut<br/> ''[[Aesculus indica]]'': Indian horse-chestnut<br/> ''[[Aesculus neglecta]]'': dwarf buckeye<br/> ''[[Aesculus parviflora]]'': bottlebrush buckeye<br/> ''[[Aesculus pavia]]'': red buckeye<br/> ''[[Aesculus sylvatica]]'': painted Buckeye<br/> ''[[Aesculus turbinata]]'': Japanese horse-chestnut<br/> ''[[Aesculus chinensis var. wilsonii]]'': Wilson's horse-chestnut<br/> ''[[Aesculus wangii]] = [[Aesculus assamica]]. }} The genus '''''Aesculus''''', the '''buckeyes''' and '''horse-chestnuts''', comprises 20–25 species of [[deciduous]] [[tree]]s and [[shrub]]s native to the temperate [[northern hemisphere]], with 7–10 species native to [[North America]] and 13–15 species native to [[Eurasia]]; there are also several [[Hybrid (biology)|hybrids]]. They have traditionally been treated in their own usually monogeneric family [[Hippocastanaceae]], but genetic evidence has led to this family, along with the [[Aceraceae]] ([[Maple]]s and ''[[Dipteronia]]''), being included in the soapberry family ([[Sapindaceae]]). The North American species are known as ''buckeyes'' and the Eurasian species as ''horse-chestnuts''. Some are also called ''white chestnut'' or ''red chestnut'' (as in some of the [[Bach flower remedies]]. In Britain, they are sometimes called ''conker trees'' because of their link with the game of [[conkers]], played with the seeds, also called conkers. == Etymology == The name horse-chestnut (hyphenated here to avoid confusion with the true [[chestnut]]s (''Castanea'', [[Fagaceae]])) is also often given as "horse chestnut" or "horsechestnut". One species very popular in cultivation, the common horse-chestnut ''Aesculus hippocastanum'' is also often known as just "horse-chestnut". Linnaeus named the genus ''Aesculus'' after the Roman name for an edible acorn. The use of the term "horse" refers to their strength or inedibility, and does not here refer to their fitness as fodder for horses, except in folk etymology. The name buckeye derives from the resemblance of the seed to the brown eye of a buck (male [[deer]]), and horse-chestnut from the external resemblance of the seed to a chestnut, but being inedible. The buckeye blooms in summer and the horse-chestnut in late spring. They tend to die right around the 1st of January every year. In Michigan, the name buckeye is also synonymous for Ohio trash. == Description == [[Image:Horse chestnut flowers.JPG|left|thumb|<Center>Horse chestnut flowers in Ayrshire, Scotland.]] ''Aesculus'' are [[woody plant]]s from 4 to 36m tall (depending on species), and have stout shoots with resinous, often sticky, buds; opposite, palmately divided leaves, often very large (to 65 cm across in the Japanese horse-chestnut ''Aesculus turbinata''); and showy insect-pollinated [[flower]]s, with four or five [[petal]]s fused into a lobed [[Corolla (flower)|corolla tube]]. Flowering starts after 80–110 [[growing degree day]]s. The fruit is a rich glossy brown to blackish-brown [[Nut (fruit)|nut]] 2–5 cm diameter, usually globose with one nut in a green or brown husk, but sometimes two nuts together in one husk, in which case the nuts are flat on one side; the point of attachment of the nut in the husk shows as a large circular whitish scar. The husk has spines in some species, spineless in others, and splits into three sections to release the nut. == Cultivation == [[Image:Aesculus carnea BotGartenMuenster PurpurKastanie 6685.jpg|thumb|left|240px|Flower of the red horse-chestnut (''[[Aesculus x carnea]]'')]] The most familiar member of the genus worldwide is the [[common horse-chestnut]] ''Aesculus hippocastanum'', native to a small area of the [[Balkans]] in southeast [[Europe]], but widely cultivated throughout the temperate world. The yellow buckeye ''Aesculus flava'' (syn. ''A. octandra'') is also a valuable ornamental tree with yellow flowers, but is less widely planted. Among the smaller species, the bottlebrush buckeye ''Aesculus parviflora'' also makes a very interesting and unusual flowering shrub. Several other members of the genus are used as ornamentals, and several horticultural hybrids have also been developed, most notably the red horse-chestnut ''A. × carnea'', a hybrid between ''A. hippocastanum'' and ''A. pavia''. They are generally fairly problem-free, though a recently discovered leaf-mining [[moth]] ''[[Cameraria ohridella]]'' is currently causing major problems in much of Europe, causing premature leaf fall which looks very unattractive. The symptoms (brown blotches on the leaves) can be confused with damage caused by the leaf fungus ''Guignardia aesculi'', which is also very common but usually less serious. Common horse-chestnut is also used as a food plant by the [[Sycamore (moth)|sycamore]], another species of moth. Another disease in parts of North West Europe and North America is [[bleeding canker]]<ref>[http://www.forestresearch.gov.uk/bleedingcanker UK Forestry Commission page on bleeding canker]</ref><ref>[http://www.kastanjeziekte.wur.nl/uk/index_uk.htm Dutch page on bleeding canker (in English)]</ref>. ==Uses== The nuts contain high concentrations of a [[saponin]]-class toxin called [[aesculin]], which is toxic to many animals including humans because it causes [[hemolysis]] (destruction of [[red blood cell]]s). The saponin can be eliminated by leaching the pulverized nuts in multiple changes of boiling water, to yield a wholesome [[starch]]y [[porridge]] once important to some [[Indigenous peoples of the Americas|Native American]] peoples. Some animals, notably [[deer]] and [[squirrel]]s, are resistant to the toxins and can eat the nuts directly. An interesting side-note is that aesculin is a natural [[pH indicator]] which, when extracted turns from colorless to fluorescent blue under [[UV light]] in an acidic [[pH]] range. California buckeye ''[[Aesculus californica]]'' is known to cause poisoning of [[honeybee]]s from toxic [[nectar]] (native [[bee]] species not being affected). Other buckeye species are thought to have the same effect, but the toxins are diluted because the trees are not usually abundant enough in any one area. {{Fact|date=January 2008}} The wood is very pale whitish-brown, fairly soft and little-used. Uses include cheap furniture, boxes and firewood.{{Fact|date=January 2008}} In [[United Kingdom|Britain]] and [[Ireland]] the game of [[conkers]] remains a common childhood pastime. In some cultures, the buckeye tree is thought to bring good luck.<!-- <ref>[http://www.ohiodnr.com/forestry/education/buckeyetrees2.htm]</ref><ref>[http://www.biosci.ohio-state.edu/~herb/buckeye.htm]</ref> -- Dead links commented out May 2008> The [[Mexican buckeye]] is related to ''Aesculus'', but is in a separate genus, ''Ungnadia''. Extractives of the seeds have been shown to be useful for the treatment of chronic venous insufficiency. <ref>[http://nccam.nih.gov/health/horsechestnut/ Horse Chestnut - Aesculus hippocastanum [NCCAM Herbs at a Glance&#93;<!-- Bot generated title -->]</ref> == References == {{reflist}} <gallery> Image:AesculusChinensis.jpg|Chinese horse-chestnut (''Aesculus chinensis'') young leaves in spring ... Image:AesculusChinensisLeaf.jpg|... and fully grown, in summer Image:Aesculus californica.jpg|California buckeye (''[[Aesculus californica]]'') leaves Image:Paardekastanje wit uitgelopen knop.jpg|''Aesculus hippocastanum'' bud opening in spring Image:Horse Chestnut Tree.jpg|[[Common horse-chestnut]] tree in winter Image:Kiev kashtan.jpg|[[Common horse-chestnut]] tree Image:Aesculus carnea BotGartenMuenster PurpurKastanie 6685.jpg|Red horse-chestnut (''Aesculus x carnea'') Image:Aesculus glabra USDA.jpg|[[Ohio buckeye]] tree (''Aesculus glabra'') </gallery> ==External links== {{commons}} *[http://www.ars-grin.gov/cgi-bin/npgs/html/genus.pl?245 Germplasm Resources Information Network: ''Aesculus''] *Forest, F., Drouin, J. N., Charest, R., Brouillet, L., & Bruneau A. (2001). A morphological phylogenetic analysis of Aesculus L. and Billia Peyr. (Sapindaceae). ''Canad. J. Botany'' 79 (2): 154-169. [http://www.ingentaconnect.com/content/nrc/cjb/2001/00000079/00000002/art00003 Abstract]. *[http://www.henriettesherbal.com/eclectic/kings/aesculus.html ''Aesculus glabra'' (Ohio buckeye)] King's American Dispensatory *[http://www.buckeyeplayingcards.com Ohio Buckeye Trivia Cards tell about the buckeye, buckeye tree, buckeye history, buckeye folklore and more.] [[Category:Sapindaceae]] [[Category:Medicinal plants]] <!-- Aesculus turbinata only --> [[bg:Конски кестен]] [[da:Hestekastanje]] [[de:Rosskastanien]] [[es:Aesculus]] [[fr:Aesculus]] [[hsb:Jěrowc]] [[it:Aesculus]] [[lb:Käschtebeem]] [[nl:Paardenkastanje]] [[ja:トチノキ]] [[pl:Kasztanowiec]] [[pt:Aesculus]] [[qu:Kawallu kastaña]] [[ru:Конский каштан]] [[sq:Aesculus]] [[sl:Divji kostanj]] [[fi:Hevoskastanjat]] [[sv:Hästkastanjesläktet]] [[tr:At kestanesi]] [[uk:Гіркокаштан]] [[zh:七叶树属]]