legume glossary

Parts of a pea flower (any flower in the legume family)

A pea flower has five petals in a bilateral arrangement (not radial).

banner: The topmost petal. It may have a crease down the middle that makes it looks like two petals stuck together, or it may be curled around the other petals. Also called the “standard petal”. [figure] [Jepson]
wing: Each of the two lateral petals below the banner, often fused at their top edge and enfolding the keel. [figure] [Jepson, plant glossary]
keel: The two bottom petals collectively, often fused at their bottom edge. May be partially or fully hidden by the wings. [figure] [Jepson]