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A Banyan (also Banian) is a fig that starts its life as an epiphyte (a plant growing on another plant) when its seeds germinate in the cracks and crevices on a host tree (or on structures like buildings and bridges). "Banyan" often refers specifically to the Indian banyan (''Ficus benghalensis)'', which is the national tree of the Republic of India,〔(【引用サイトリンク】 title=National Tree )〕 though the term has been generalized to include all figs that share a characteristic life cycle, and systematically to refer to the subgenus ''Urostigma''.〔Note usage of "Banyan" versus "banyan" in by Vidya R. Athreya, ''Nature Watch,'' July 1997; also ("Aerial-rooting banyan trees" ), washington.edu〕 Like other fig species (including the common edible fig ''Ficus carica''), banyans bear multiple fruit in structures called syncarps. The ''Ficus'' syncarp supplies shelter and food for fig wasps and in turn, the trees are dependent on the fig wasps for pollination. The seeds of banyans are dispersed by fruit-eating birds. The seeds are small, and most banyans grow in forests, so that a plant germinating from a seed that lands on the ground is unlikely to survive. However, many seeds land on branches and stems of trees or on buildings. When those seeds germinate they send roots down towards the ground, and may envelop part of the host tree or building structure, giving banyans the casual name of "strangler fig". The "strangling" growth habit is found in a number of tropical forest species, particularly of the genus ''Ficus,'' that compete for light. 〔Zhekun, Zhou & Michael G. Gilbert (2003) Flora of China (Moraceae) 5: 21-73. (Harvard.edu )〕〔Serventy, V. 1984. Australian Native Plants. Victoria: Reed Books.〕〔Light in the rainforest 1992 Tropical topics. Vol 1 No. 5 (QLD.gov.au )〕 Any ''Ficus'' species showing this habit may be termed a strangler fig. The leaves of the banyan tree are large, leathery, glossy green and elliptical in shape. Like most fig-trees, the leaf bud is covered by two large scales. As the leaf develops the scales fall. Young leaves have an attractive reddish tinge.〔(The Lovely Plants. )〕 Older banyan trees are characterized by their aerial prop roots that grow into thick woody trunks which, with age, can become indistinguishable from the main trunk. Old trees can spread out laterally, using these prop roots to cover a wide area. In some species the effect is for the props to develop into a sort of forest covering a considerable area, every trunk connected directly or indirectly to the central trunk. The topology of this structure of interconnection inspired the name of the hierarchical computer network operating system Banyan VINES. In a banyan that envelops a support tree the mesh of roots growing round the support tree eventually applies very considerable pressure and commonly kills the tree. Such an enveloped dead tree eventually rots away so that the banyan becomes a "columnar tree" with a hollow central core. In jungles such hollows are particularly desirable shelters to many animals. ==Etymology== The name was originally given to ''F. benghalensis'' and comes from India where early travellers observed that the shade of the tree was frequented by ''banias'' or Indian traders.〔Yule, Henry, Sir. Hobson-Jobson: A glossary of colloquial Anglo-Indian words and phrases, and of kindred terms, etymological, historical, geographical and discursive. New ed. edited by William Crooke, B.A. London: J. Murray, 1903.〕 In the Gujarati language, banya means "grocer/merchant," not "tree." The Portuguese picked up the word to refer specifically to Hindu merchants and passed it along to the English as early as 1599 with the same meaning. By 1634, English writers began to tell of the banyan tree, a tree under which Hindu merchants would conduct their business. The tree provided a shaded place for a village meeting or for merchants to sell their goods. Eventually "banyan" became the name of the tree itself. 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「Banyan」の詳細全文を読む スポンサード リンク
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