CAPPARALES

caper order of dicotyledonous flowering plants, a division of the subclass Dilleniidae. the diverse caper order of flowering plants, belonging to the class called Magnoliopsida, or the dicotyledons (q.v.). It is composed of 427 genera and about 4,000 species in five families. The more commonly known members of this order belong to the caper (Capparaceae) and the mustard (Brassicaceae) families. The Brassicaceae family is widespread and is native to the temperate and arctic regions of North America. Its members are chiefly annual or perennial herbs. Their habitats are diverse, but cultivated mustards thrive in rich garden soil. It is a family of considerable economic importance, containing such cool-weather food plants as radish (Raphanus sativus) and Chinese cabbage (Brassica rapa). Horticultural varieties of the cabbage group B. oleracea include collards, kale, broccoli, cauliflower, head and Savoy cabbages, Brussels sprouts, and kohlrabi. Various turnips belong to subgroups of B. rapa. The black mustard (B. nigra) is the main source of table mustard. Many other members of this family are grown as ornamentals, including stock (Matthiola incana), sweet alyssum (Lobularia maritima) and the candytufts (Iberis). The genera Capparis, Cleome, and Crateva of the Capparaceae are native to the tropics. Fifteen genera are restricted to Africa. Other members are indigenous to Australia and Asia; a few belong to the New World. The economic value of the caper family is low. The European caperbush (Capparis spinosa) is known for its flower buds pickled in vinegar and used as a spicy condiment. Buds of C. decidua are eaten as potherbs, and curries are prepared from seeds and fruits of Capparis zeylandica and Cleome icosandra. Although several species of Capparales reproduce vegetatively, the major form of propagation is sexual. In the caper and mustard families, flowers usually are clustered in inflorescences; in several smaller families, flowers arise singly at the juncture of leaf and stem. Flowers are bisexual (containing both male and female organs), with numerous to few stamens and an ovary of two or more fused carpels. Following pollination and fertilization, the ovule becomes the seed, and the ovary the fruit. Additional reading J.G. Vaughan, A.J. MacLeod, and B.M.G. Jones (ed.), The Biology and Chemistry of the Cruciferae (1976); P. Feeny, Defensive Ecology of the Cruciferae, Annals of the Missouri Botanical Garden, 64:221234 (1977).