sweet pea, annual climbing plant ( Lathyrus odoratus ) of the family Leguminosae (pulse family), a legume native to S Europe but, since its introduction to horticulture c.1700, widely cultivated for its fragrant flowers. There are three main types: dwarf, summer flowering (garden sweet peas), and winter flowering (florists' sweet peas). As cut flowers, sweet peas are one of the more important of florists' plants and are available in a wide range of shades. The vines climb by tendrils and require support. The sweet pea is also a honey plant and the source of an essential oil used in perfumery, although today this oil is more often made synthetically. The green pea and chickpea are related but of separate genera. The term pea is sometimes used generally for a seed in the pod of any leguminous plant. Sweet peas are classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Leguminosae.