∙ Papilionaceous corolla is the petals whorl present in the flowers of Papilionaceae (sub-family of Fabaceae family).
∙ Papilionaceous corolla is a very different kind of aestivation in which five petals are present.
∙ The largest petal is known as Vexillum or Standard and it overlaps two lateral petals called wings which further overlap two small anterior leaves called the keel.
∙ Thus, there is one vexillum, two wings, and two keels present in the papilionaceous corolla.