PAPAVERALES

the poppy order of flowering plants, belonging to the class known as Magnoliopsida (dicotyledons; characterized by the presence of two seed leaves). The order is composed of about 600 species in two families, Papaveraceae and Fumariaceae. Its most familiar flowers are the poppy (q.v.) of the Papaveraceae and the bleeding heart (q.v.) of the Fumariaceae. This order mostly is herbaceous (nonwoody) and is distributed worldwide, primarily in temperate regions. Features that characterize the Papaveraceae family are regular (radially symmetrical) flowers, bud-enclosing sepals, and regularly inserted stamens. Although some are treelike, the majority of Papaveraceae are annual or perennial herbs. Members of the Papaver genus include P. somniferum, which yields opium. Members of the Fumariaceae family develop irregular (bilaterally symmetrical) flowers, with small sepals and six stamens in two groups. The family is valued for the beauty of its members' flowers. In several species of Papaverales, rhizomes (horizontal stems), taproots, bulblets, and tubers give rise to colonies of plants. The major method of reproduction, however, is by sexual means. Flowers in the poppy family develop in four or more whorls, with two sepals, 4 to 6 (or 8 to 12) petals, numerous stamens, and a pistil composed of many joined carpels. Green sepals shed as the flower opens. Ovules arise along ridges on the inside of the one-chambered, superior ovary, and there are numerous seeds. Some flowers are self-pollinated in the closed condition, but insects, especially bees, facilitate cross-pollination in most species. After fertilization, the ovary becomes the fruit.