Papaverales

(botany) An order of dicotyledonous plants in the subclass Magnoliidae, marked by a syncarpous gynoecium, parietal placentation, and only two sepals.

An order of flowering plants, division Magnoliophyta (Angiospermae), subclass Magnoliidae of the class Magnoliposida (dicotyledons). The order consists of only two families: Papaveraceae with some 200 species, and Fumariaceae with about 400 species. Within its subclass, the order is marked by its syncarpous gynoecium, parietal placentation, and only two (seldom three) sepals. Most of the species are herbaceous, and many of them contain isoquinoline alkaloids similar to those in the order Ranunculales. The Papaveraceae, with regular flowers, numerous stamens, and a well-developed latex system, include the poppies (Papaver and related genera), bloodroot (Sanguinaria), and celandine (Chelidonium). Papaver somniferum is the source of opium. The Fumariaceae, with four or six stamens, irregular flowers that usually have some of the petals spurred or saccate, and no latex system, include the bleeding heart (Dicentra spectabilis) and some other common ornamentals. See also Magnoliidae; Magnoliophyta; Magnoliopsida; Poppy; Ranunculales.