\Pa*pil`io*na"ceous\, a.
1. Resembling the butterfly.
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
       ({Papilionace[ae]}) which includes the bean, pea,
       vetch, clover, and locust.