1. of or relating to plants of the legume family (Fabaceae) that have flowers with a distinctive shape resembling a butterfly, consisting of a large upper petal (banner), two side petals (wings), and two lower petals fused together (keel)
Usage: botanical term; commonly used in plant classification and horticulture

Examples

• The papilionaceous flowers of the pea plant are easily recognized by their distinctive butterfly-like shape.
• Clover displays papilionaceous blooms that attract bees and other pollinators.
• Many papilionaceous plants are nitrogen-fixing and improve soil fertility.
• The garden featured several papilionaceous species, including lupines and sweet peas.
• Botanists classify beans and peas as papilionaceous because of their characteristic flower structure.
• The papilionaceous family includes economically important crops like soybeans and lentils.