papilionaceous

a. 1. Resembling the butterfly. [ 1913 Webster ]

2. (Bot.) (a) Having a winged corolla somewhat resembling a butterfly, as in the blossoms of the bean and pea. (b) Belonging to that suborder of leguminous plants (Papilionaceæ) which includes the bean, pea, vetch, clover, and locust. [ 1913 Webster ]