winged bean

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A twining tropical plant (Psophocarpus tetragonolobus) in the pea family, having pods with four winglike ridges and cultivated for its edible roots, leaves, pods, and seeds.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A tropical legume, Psophocarpus tetragonolobus, having clusters of purple flowers and pods with four jagged wings

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a tuberous twining annual vine bearing clusters of purplish flowers and pods with four jagged wings; Old World tropics