in botany, a genus of the polyandria monogynia clas. The corolla consists of four petals, and the calyx of two leaves. There are nine species, fix of them natives of Britain, viz. the hybridum, or round rough-headed poppy; the cambricum, or yellow poppy; the somniferum, or wild poppy; the ergemone, or long rough-headed poppy; the rhoeas, or red corn-poppy; and the dubium, or long smooth-headed poppy. For the medical properties of poppy, see OPIUM.