They are widely distributed in the tropics and subtropics; very few species occur in Asia (about 1,385 species), particularly in the Indo-Malayan region, and in tropical America (about 1,147 species). especially in northeastern South America. Only about 117 species are native to Africa. One of the hardiest of the tree palms is the windmill palm, Trachycarpus fortunei, of eastern Asia, which is cultivated outdoors in milder maritime climates as far north as Vancouver, Canada. The most cold-tolerant palm is the needle palm, Rhapidophyllum hystrix of the southeastern United States: it can survive temperatures of 21 C (-6 F).
In addition to the commonly recognized treelike forms, which may reach 30 m (100 ft) high, there are those with stems completely underground and those with vine like steams. The long, thin, rope like stems of the rattan palms, Calamus and Daemonorops, which may climb 60 m (200 ft) into the treetops, are the rattan cane used commercially. The leaves of the faffia palms, Raphia, are the largest in the plant kingdom, exceeding 20 m (65 ft) in length, and are the source of raffia fiber.
Palm flower are typically small and may be borne singly, in pairs, in threes (triads), in small clusters (cincinni), in small lines (acervuli), or in large clusters (panicles). The flower cluster or segments are often enclosed at their bases by a leaflike spathe (bract), which is frequently yellowish in color. Palm flowers may be bisexual but are usually unisexual. Palm trees are usually monoecious, bearing both mare and female unisexual flowers on the same tree, but some species are dioecious, with separate male and female trees, or polygamous, with both unisexual and bisexual flowers on the same tree. Palm fruit is botanically a berry, nut, or drupe, depending in part upon the structure of the flower ovary. The coconut (with husk) is a drupe, a fruit technically like that of the peach but dry and fibrous instead of fleshy. Since prehistory, palms have provided thatch for shelter; fibers for weaving, plaiting, and basketry; timber for constructing buildings, tools, and utensils; leaves for clothing and food; and sap for beverage. Throughout tropical Asia the commonest palm product in use is the fruit of the betel-nut palm, Areca Catechu, which is chewed as a stimulant.
The sap drawn tapping the unopened flower buds of several kinds of palm produces palm wine, or toddy, as from Caryota urens; an alcoholic beverage called arrack, from Cocos nucifera; or sugar, from Borassus flabellifer and Arenga pinnata. Formost among African palms is the date palm, Phoenix dactylifera, cultivated since ancient times throughout the Middle East.
Many countries use palm oil - as a vegetable oil, in Margarine and sweets, in in pharmaceuticals, and in the manufacture of soaps, candles, and lubricating greases. The oil palm tree, Elaeis guineensis native to Africa but now widely cultivated in others areas, is the most important source of palm oil.
