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''Attalea'' is a large genus of palms native to Mexico, the Caribbean, Central and South America. This pinnately leaved, non-spiny genus includes both small palms lacking an aboveground stem and large trees. The genus has a complicated taxonomic history, and has often been split into four or five genera based on differences in the male flowers. Since the genera can only be distinguished on the basis of their male flowers, the existence of intermediate flower types and the existence of hybrids between different genera has been used as an argument for keeping them all in the same genus. This has been supported by a recent molecular phylogeny. Somewhere between 29 and 67 species are recognised in the genus, with estimates of as many as 100. Incomplete herbarium collections make it difficult to determine whether certain groups represent single species, or groups of similar species. ''Attalea'' species have a long history of human use, and include economically important sources of palm oil and fibre. Many species are fire tolerant and thrive in disturbed habitats. Their seeds are animal dispersed, including some which are thought to have been adapted for dispersal by now-extinct Pleistocene megafauna. ==Description== The genus ''Attalea'' has pinnately compound leaves—rows of leaflets emerge on either side of the axis of the leaf in a feather-like or fern-like pattern. Species are also non-spiny palms and includes both large trees with stout stems up to tall and acaulescent palms (one which lack an aboveground stem). The number of leaves per individual varies from about three to thirty-five; larger plants tend to have more and longer leaves.〔 Inflorescences are large, branched and borne among the leaves.〔 The inflorescence consists of a main axis—the peduncle and the rachis—and a series of smaller branches, the rachillae. The rachillae, which bear the flowers, emerge from the rachis. The peduncle is the main stalk, connecting the rachis with the stem. Inflorescences either consist entirely of male flowers, or are predominantly female with a few male flowers.〔 Fruit usually have two or three seeds, although fewer or more are present in some species, and are usually brown, yellow, orange-brown or purple when mature.〔 Four different types of male flowers exist. On the basis of these flower types, the genus has often been split into four genera—a more narrowly defined ''Attalea'', ''Orbignya'', ''Maximiliana'' and ''Scheelea''.〔 The species sometimes referred to ''Orbignya'' have coiled anthers, while the other groups have straight ones. The petals of those placed in ''Maximiliana'' are much shorter than the stamens, while those placed in ''Scheelea'' and a more narrowly defined ''Attalea'' have petals that are longer than the stamens.〔 Five species do not fit easily into any of these groups; this fact has been used as an argument in favour of considering this group a single genus.〔 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「Attalea (palm)」の詳細全文を読む スポンサード リンク
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