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.
Introduced; subtropical and tropical, s North America (including Mexico), West Indies, Central America, South America.
Species ca. 6 (1 in the flora).