Source : WordNet®

snail bean
     n : perennial tropical American vine cultivated for its racemes
         of showy yellow and purple flowers having the corolla
         keel coiled like a snail shell; sometimes placed in genus
         Phaseolus [syn: {snailflower}, {snail-flower}, {snail
         flower}, {corkscrew flower}, {Vigna caracalla}, {Phaseolus
         caracalla}]