in botany, a genus of the polygamia monoecia clas. The hermaphrodite flower has no calyx; the corolla has 5 petals; it has many stamina, and 3 styli; the male has likewise no calyx; the corolla has 4 petals; and has a great number of stamina. There is but one species of begonia, viz. the obliqua, a native of India.