PALM

any flowering plant of the order Arecales and of the single family in the order, Arecaceae (Palmae). Many of the approximately 2,800 known species of the order are economically important. Palms furnish food, shelter, clothing, timber, fuel, building materials, fibres, starch, oils, waxes, wines, and a host of minor products for indigenous populations in the tropics. Palms are chiefly tropical and subtropical trees, shrubs, and vines, usually having a tall, unbranched, columnar trunk. The trunk is crowned by a tuft of large, pleated, fan- or feather-shaped leaves with stout sheathing and often prickly petioles (stalks), the persistent bases of which frequently clothe the trunk. The small, usually unisexual flowers are produced in large clusters. The stem, or trunk, may vary from the length and width of a pencil to a height of about 60 m (about 200 feet) and a diameter of about 1 m. The leaves may vary in length from several centimetres to more than 9 m. Seeds may be smaller than a match head or the size of a large melon. The great centres of palm distribution are tropical America (with more than 500 species concentrated in Brazil alone) and tropical Asia. Among the most important palms are: Arenga pinnata (saccharifera), the sugar palm, occurs in Malaysia. It grows about 12 m tall and frequently has 20 to 28 feather-shaped leaves. Sugar, wine, and arrack, a distilled liquor, are processed from the sap. Sago, a starch, is made from the pith. The leaves yield a moisture-resistant fibre. Attalea cohune (cohune palm), occurring in Central America, grows about 18 m (60 feet) tall and has erect, plume-shaped leaves. Oil from the seeds is used in soap. The related A. funifera of the Amazon region of South America yields a water-resistant fibre. Borassus flabellifer (palmyra palm), occurring in tropical Asia, grows about 20 m tall and has fan-shaped leaves. Fibre from various parts of the plant are made into brooms, hats, and mats. The fruits and seeds are edible. Chrysalidocarpus lutescens (areca palm), native to Madagascar, sometimes is grown indoors as an ornamental. It grows to about 10 m (33 feet) and has feather-shaped leaves about 60 cm (2 feet) long. Coccothrinax argentea (garberi), biscayne, or silver, palm, is a stemless species native to the southeasternmost United States. The fan-shaped leaves are silvery beneath. Cocos nucifera, coconut palm, originated in Malaysia but has been widely distributed in tropical coastal regions. The tree grows about 30 m tall and has feather-shaped leaves. The nuts40 to 100 are produced each yeargrow to about 25 cm (10 inches) in diameter. The fibre of the nut husk is called coir (q.v.). The liquid in the core of the nut is a tasty beverage, and the white meat of the nut is eaten raw. The meat is shredded and dried to make copra, from which coconut oil may be extracted. The meat is also grated, mixed with water, and pressed to obtain coconut milk, used in cooking or as a substitute for cow's milk. Palm wine, arrack, and vinegar are made from sap of the flower stalk. Baskets and mats are made from the leaves. The trunk yields a useful timber. Copernicia cerifera (carnauba wax palm), occurring in tropical South America, grows to about 10 m tall and has fan-shaped leaves. The trunk is swollen near the base. Carnauba waxused in polishes, varnishes, and candlesis obtained from the leaves. Elaeis guineensis (African oil palm), occurring in western and central Africa, grows to a height of 18 m or more. It bears black, oval-shaped fruit in clusters of 200 to 300. Palm oil is obtained from the fruit coat and kernel oil from the seed. Hyphaene thebaica (doum palm), an African species, is unusual because of its manybranched stem. It is known in some areas as Egyptian doom palm and gingerbread tree. Lodoicea maldivica (callipyge), commonly called coco de mer (q.v.), or double coconut, occurs in the Seychelles Islands of the Indian Ocean. It grows to about 30 m tall. Phoenix dactylifera (date palm), native to the Middle East and cultivated for its fruit since about 6000 BC, grows 30 m tall and has feathery leaves. A tree may bear as much as 250 kg (550 pounds) of dates (see date palm) annually for 100 years or more. Roystonea regia (royal palm), an erect, beautiful species native to the southeastern United States, the West Indies, and tropical America, grows to about 30 m tall and has graceful feathery leaves and a smooth, pale gray trunk resembling concrete in colour and texture. It is often grown as an ornamental. Sabal palmetto (cabbage palmetto), occurring in the southeastern United States and the West Indies, grows to about 24 m tall and has fan-shaped leaves. The water-resistant trunk is used as wharf piling; the trees are commonly grown for shade and as ornamentals along avenues. The buds are edible, mats and baskets are sometimes made from the leaves, and stiff brushes are made from the stems. S. texana, a similar species, occurs in the southwestern United States and in Mexico. Coconut palms (Cocos nucifera). any member of the Arecaceae, or Palmae, the single family of monocotyledonous flowering plants of the order Arecales, subclass Arecidae. Additional reading Michael J. Balick (ed.), The PalmTree of Life: Biology, Utilization, and Conservation (1988), detailed discussions of a number of important palms, with a section on worldwide endangerment of useful palms; Michael J. Balick, Systematics and Economic Botany of the Oenocarpus-Jessenia (Palmae) Complex (1986), a treatment of two important American oil palms; Michael J. Balick et al., Useful Palms of the World: A Synoptic Bibliography (1990), an extensive annotated list of uses of palms, incomplete but very informative; A. Henderson, A Review of Pollination Studies in the Palmae, The Botanical Review, 53(3):221259 (1986), a recent summary that shows which genera have been studied and the diversity of mechanisms; David Jones, Palms in Australia (1984), a horticultural treatment that provides a good, well-illustrated, nontechnical introduction, giving for each palm a short description, notes, distribution, distinguishing features, confusing species, cultivation, and propagation; H. Borgtoft Pedersen and H. Balslev, Ecuadorean Palms for Agroforestry (1990), an enlightening discussion of the potential of palms in agroforestry; P.B. Tomlinson, The Structural Biology of Palms (1990), a masterful, detailed synthesis of palm structure, its biological implications, and the author's prognosis for the future; H.E. Moore and Natalie W. Uhl, Major Trends of Evolution in Palms, The Botanical Review, 48:169 (1982); Natalie W. Uhl and John Dransfield, Genera Palmarum (1987), a classification reference book, including treatment of morphology, anatomy, fossil record, distribution, ecology, and evolution.