EBENALES

ebony order of flowering plants, belonging to the class Magnoliopsida (dicotyledons; characterized by two seed leaves). It comprises five families, as many as 145 genera, and about 1,700 species of trees and shrubs, distributed chiefly in the tropics. Only three of the familiesEbenaceae (ebony), Sapotaceae (sapodilla), and Styracaceae (storax)are of economic importance. The overwhelming majority of the Ebenales grow in hot, humid forests of the tropics. Only a few members, such as the common persimmon (Diospyros virginiana) of the eastern United States and the Asian date plum (D. lotus), thrive in fairly dry soils. The order is distinguished, in part, by its woodiness, simple leaves, attachment of stamens (pollen-producing organs) to the petals, and the production of only a few ovules within each chamber of the ovary. The ebony family, Ebenaceae, consists of trees and shrubs that shed their leaves in autumn and develop heartwood that often is black, red, or green in colour. Its six genera and approximately 450 species are native to the tropics of both hemispheres, with extensions into warm temperate regions. The large Macassar ebony tree (Diospyros ebenum) of India and the East Indies yields the most commercially valuable ebony wood. Its black heartwood, streaked with brown, contains fibres filled with a hard gum that makes it heavy enough to sink in water. This close-grained wood is difficult to work but assumes a beautiful metallic sheen when polished; it is used primarily for flutes, black piano keys, wood inlays, knife handles, cabinets, and sculpture. Several persimmons produce prized fruits. These include the Japanese persimmon (D. kaki), grown in the Orient, the Mediterranean region, and the warmer parts of the southern United States; the black sapote (D. digyna, formerly D. ebenaster), with its dark brown, highly palatable fruits; and D. virginiana, a seedy persimmon that is native to the United States. The sticky, milky latex of plants of the Sapotaceae (sapodilla) family differentiates it from other families in the Ebenales. Of its approximately 126 genera and approximately 800 species, several representatives are of economic importance, including Pouteria, the white balata; Manilkara, the red balata; M. bidentata, the bully tree, possessing purple heartwood that is known as bulletwood; and other timber trees. The sapodilla (Achras zapota), native to southern Mexico, produces a luscious, fragrant fruit. Its trunk also yields chicle, a gum that serves as the base for many chewing gums. The tree is now cultivated in India, Hawaii, and parts of Africa. Edible oils are extracted from many seeds of the sapodilla family, including those of Butyrospermum paradoxum, grown on the savannas of the Sudan and the Nile River regions, and those of Argania spinosa, the Morocco ironwood. Certain species of Payena, found in Thailand and nearby regions, are tapped for latex, which is processed into gutta-percha. The storax family, Styracaceae, is identified by star-shaped hairs on leaves and by fleshy fruits that develop an internal stony layer (drupe). This is in contrast to the fully fleshed fruits (berries) of the other families. Trees and shrubs of its 10 genera and 150 species generally are smaller than those of the ebony and sapodilla families. Three genera native to China furnish species grown for ornament. The Malayan Styrax benzoin produces the resin benzoin, used as a base in perfumes, as a soothing medicine, and as an antiseptic. Inflorescences in the Ebenales vary from small clusters (and even solitary flowers) in the ebony and sapodilla families to branched types (panicles and cymes) in the more primitive Styracaceae and Symplocaceae. An idealized flower of this order consists of four whorls. Sepals, petals, and stamens each number four or five. Sepals and petals of a whorl are joined laterally to form, respectively, an urn- or bell-shaped calyx and corolla. The pistil consists of two to five carpels differentiated into a basal ovary, a single style, and stigma lobes corresponding in number to the chambers in the ovary. No more than two ovules are borne centrally in each chamber. In the ebony family functional stamens and pistils seldom are developed in the same flower. Male flowers produce pollen, but the pistil is undeveloped; conversely, the female flower has a fully developed pistil, but contains abortive stamens. The flowers are borne on separate trees, but in each case a few perfect flowers develop, possessing both male and female units, thereby assuring that isolated plants may bear fruit. Following pollination and fertilization, the ovule becomes the seed and the ovary the fleshy fruit. Sepals and petals often appear in two series in the Sapotaceae and may number up to 12. Flower parts in both the Symplocaceae and the Lissocarpaceae arise from the top of the ovary, unlike the flower parts in the other families.