The pea-like flowers of vicia sativa
grow from the middle to upper leaf nodes, one, two or three blooms per node. They have a wide, two-lobed light purple or pink outer petal (the banner), over one inch across, with purple veins, enclosing two smaller, darker-colored inner petals (the wings) and two even smaller fused petals (the keel). The freely branched stems are long and rigid, reaching heights of 6 feet or more, and have a square cross-section. Stalks of the compound leaves terminate in a branched tendril. There are four subspecies of vicia sativa (cordata, nigra, sativa and segetalis), differing in leaf shape and flower characteristics.