|
The genus ''Aesculus'' (〔''Sunset Western Garden Book,'' 1995:606–607〕 or ) comprises 13–19 species of trees and shrubs native to the temperate Northern Hemisphere, with 6 species native to North America and 7–13 species native to Eurasia; there are also several hybrids. ''Aesculus'' exhibits a classical arcto-Tertiary distribution. The genus has traditionally been treated in the ditypic family Hippocastanaceae along with ''Billia'',〔Hardin, JW. 1957. A revision of the American Hippocastanaceae I. Brittonia 9:145-171.〕 but recent phylogenetic analysis of morphological〔Judd, WS, RW Sanders, MJ Donoghue. 1994. Angiosperm family pairs. Harvard Papers in Botany. 1:1-51.〕 and molecular data has caused this family, along with the Aceraceae (Maples and ''Dipteronia''), to be included in the soapberry family (Sapindaceae). Linnaeus named the genus ''Aesculus'' after the Roman name for an edible acorn. Common names for these trees include "buckeye" and "horse chestnut". 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. ''Aesculus'' seeds were traditionally eaten, after leaching, by the Jōmon people of Japan over about four millennia, until 300 AD.〔Harlan cites Akazawa, T & Aikens, CM, ''Prehistoric Hunter-Gathers in Japan'' (1986), Univ. Tokyo Press; and cites Aikens, CM & Higachi, T, ''Prehistory of Japan'' (1982), NY Academic Press.〕 All parts of the buckeye or horse chestnut tree are moderately toxic, including the nut-like seeds.〔Hall, Alan. 1976. The Wild Food Trail Guide. Second edition. Holt, Rhinehart and Winston, New York, pp.214.〕 〔Peterson, Lee. 1977. A Field Guide to Edible Wild Plants of Eastern and Central North America. Houghton Mifflin Co., Boston, pp172.〕 The toxin affects the gastrointestinal system, causing gastrointestinal disturbances. The USDA notes that the toxicity is due to saponin aescin and glucoside aesculin, with alkaloids possibly contributing.〔Nelson, Guy. 2006. Ohio Buckeye (Aesculus glabra Willd.). Plant Guide, US Department of Agriculture, Natural Resources Conservation Service, Washington, D.C.〕 Native Americans used to crush the seeds and the resulting mash was thrown into still or sluggish waterbodies to stun or kill fish. 〔Nelson, Guy. 2006. Ohio Buckeye (Aesculus glabra Willd.). Plant Guide, US Department of Agriculture, Natural Resources Conservation Service, Washington, D.C.〕〔 Thomas, R. Dale, and Dixie B. Scogin. 1988. 100 Woody Plants of Louisiana. Contributions of the Herbarium of Northeast Louisiana University, Monroe, Louisiana, pp.118.〕 They would then boil and drain (leach) the fish at least three times in order to dilute the toxin's effects. New shoots from the seeds also have been known to kill grazing cattle. == Description == ''Aesculus'' species have stout shoots with resinous, often sticky, buds; opposite, palmately divided leaves, often very large—to across in the Japanese horse chestnut ''Aesculus turbinata''. The seeds of the Aesculus are traditionally used in a game called conkers in Europe. Species are deciduous or evergreen. Flowers are showy, insect- or bird-pollinated, with four or five petals fused into a lobed corolla tube, arranged in a panicle inflorescence. Flowering starts after 80–110 growing degree days. The fruit matures to a capsule, diameter, usually globose, containing one to three seeds (often erroneously called a nut) per capsule. Capsules containing more than one seed result in flatness on one side of the seeds. The point of attachment of the seed in the capsule (hilum) shows as a large circular whitish scar. The capsule epidermis has "spines" (botanically: prickles) in some species, while other capsules are warty or smooth. At maturity, the capsule splits into three sections to release the seeds.〔Hardin, JW. 1957. A revision of the American Hippocastanaceae I. Brittonia 9:145-171〕〔Hardin, JW. 1957. A revision of the American Hippocastanaceae II. Brittonia 9:173-195〕〔Hardin, JW. 1960. A revision of the American Hippocastanaceae V, Species of the Old World. Brittonia 12:26-38〕 The species of ''Aesculus'' include: * ''Aesculus arguta'': Aesculus glabra * ''Aesculus californica'': California buckeye (western North America) * ''Aesculus × carnea'': red horse chestnut * ''Aesculus chinensis'': Chinese horse chestnut (eastern Asia) * ''Aesculus chinensis var. wilsonii'': Wilson's horse chestnut (eastern Asia) * ''Aesculus flava'' (''A. octandra''): yellow buckeye (eastern North America) * ''Aesculus glabra'': Ohio buckeye (eastern North America) * ''Aesculus hippocastanum'': common horse chestnut (Europe, native to the Balkans) * ''Aesculus indica'': Indian horse chestnut (eastern Asia) * ''Aesculus neglecta'': dwarf buckeye (eastern North America) * ''Aesculus parviflora'': bottlebrush buckeye (eastern North America) * ''Aesculus parryi'': Parry's buckeye (western North America, endemic in Baja California del Norte) * ''Aesculus pavia'': red buckeye (eastern North America) * ''Aesculus pavia var. flavescens'': Texas yellow buckeye, yellow woolly buckeye (eastern North America, narrowly endemic in Texas) * ''Aesculus sylvatica'': painted buckeye (eastern North America) * ''Aesculus turbinata'': Japanese horse chestnut (eastern Asia, endemic in Japan) * ''Aesculus wangii: Aesculus assamica (eastern Asia) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Aesculus」の詳細全文を読む スポンサード リンク
|