common name for the family Papaveraceae, a small group of herbaceous flowering plants occurring principally in the North Temperate Zone, and for its representative genus, Papaver. The family contains about 23 genera and 210 species; many are important as ornamentals, and one species is the source of OPIUM, (q.v.). Members of the family occupy varied habitats, but they are more common in open, well-drained areas. This preference helps explain why several members of the family, especially poppies, are bothersome weeds in cultivated fields. See also BLOODROOT,.

The genus Papaver contains about 50 species. The Oriental poppy, P. orientale, is widely cultivated as an ornamental, and many color forms have been developed. The opium poppy, P. somniferum, produces several useful products. Its tiny seeds, produced in huge quantities in each of the plant’s dry fruits, or capsules, are used in baking and produce an important drying oil. Opium is the dried sap, or latex, that is harvested from the capsules while they are still young. It contains many alkaloids, including morphine and CODEINE, (q.v.), that are useful in medicine. Heroin is synthesized from the morphine purified from the complex mixture of alkaloids in opium (see DRUG DEPENDENCE,).

The family Papaveraceae shares the order Papaverales with the family Fumariaceae (see FUMITORY,). This family contains about 16 genera and 400 species, also mostly found in the North Temperate Zone with a few species located in mountainous regions of tropical Africa and South Africa. The most familiar member of the family is the BLEEDING HEART (q.v.); others are of minor ornamental importance.

The leaves are usually deeply divided and arranged in a rosette around the base of the short stem. The flowers have two to four sepals (outer floral whorls) and twice as many petals (inner floral whorls). The stamens (male floral organs) vary in number from six to many more, and the ovary (female floral organ) is superior (borne above and free from the other flower parts). The order characteristically has sap that is rich in alkaloids. The sap is clear and watery in the fumitory family, milky in the poppy family.

Plants in the order Papaverales are members of the class Magnoliopsida (see DICOTS,) in the phylum or division Magnoliophyta (see ANGIOSPERM        M.R.C., MARSHALL R. CROSBY, Ph.D.

For further information on this topic, see the Bibliography, sections 452. Plants, 503. Medications–504. Drug abuse, 592. Horticulture.