Plant twiner; stem smooth or sparsely hairy, often muriculate; leaves simple, ovate, base broadly cordate, acute at apex, margins entire, crenate or shallowly lobed (sometimes deeply 3 lobed), glabrous or sparsely pubescent; flowers small, axillary, in dense cymes; bracts small, caducous; calyx broadly obovate to spathulate, ultimately spreading, sepals-5, free, notched at the apex, glabrous or pilose; corolla yellow, campanulate, 5-plaited, glabrous within; stamens-5, epipetalous, slightly exserted, hairy below; ovary 2-4 locular, globose, glabrous, style short, stout, stigma globose; capsules broadly conical to depressed, globose, somewhat angled, reticulate, glabrous; seeds trigonous, globose, blackish, brown, puberulent or woolly along angles and at hilum.