Perennial, extensive, dioecious, climber; roots tuberous; stem slender, much branched, 5-angular or grooved; tendrils simple; leaves alternate, cordate, ovate, acute, entire, variously lobed, glabrous, often punctuate beneath; petiole without glands; flower solitary, at the apex of peduncle with a bract large, thin or thick, soft pubescent, embracing the expanded flower; calyx-tube short, linear, acute, densely villous; petals-5, yellow, oblong-obtuse, spreading, prominently veined: stamens 3, connate, 2-anthered filaments bifid half way down; female flowers on peduncle as long as in male; bract small near the base; calyx and corolla as in male flowers; ovary fusiform, rostrate, muricate; ovules many, 3-placentiferous; style slender; stigma-3, entire or bifid; fruits ovoid-ellipsoid, acute or shortly beaked, without ribs, densely echinate with soft spines, indehiscent; seeds many, compressed, broad oblong, pale yellow with a few well marked corrugations on the margins.