Capacity for forming storage roots of 189 Psophocarpus tetragonolobus (L.) DC. and three P. scandens (Endl.) Verc. accessions was evaluated after one year's growth at Homestead, Florida. None of the P. scandens accessions formed storage roots whereas 38 of the P. tetragonolobus accessions showed storage root formation. Great differences in tuber production were observed among the accessions. The environmental component of the phenotypic variance for storage root production appears to be very large. Protein content of the storage roots ranged from 8 to 31 per cent on a dry weight basis (mean 16 per cent.).