Vines, perennial [annual]; roots tuberous. Stems scandent, tendril-bearing, pubescent or glabrous; tendrils terminal and axillary, branched. Leaves deciduous or persistent, cauline, alternate, petiolate; ocrea usually deciduous, chartaceous; blade broadly ovate to deltate or truncate, margins entire, sometimes undulate. Inflorescences terminal and axillary, often clustered near tips of stems, racemelike, pedunculate. Pedicels present. Flowers bisexual, (1-)2-5 per ocreate fascicle, base stipelike; perianth accrescent in fruit, pink to purple or, rarely, white or yellowish, campanulate, glabrous; tepals 5, connate proximally, petaloid, dimorphic, outer 3 broader than inner 2; stamens (7-)8(-9); filaments connate ca. 1/ 2 their length, forming staminal tube, adnate to perianth tube, glandular-pubescent; anthers yellow to reddish, ovate to elliptic; styles 3, recurved, distinct; stigmas reniform-capitate. Achenes included in membranous perianth, brown, unwinged, subglobose to bluntly 3-gonous proximally, 3-gonous distally, glabrous or pubescent. Seeds: embryo straight. x = 20.