Monoecious; fls 5-merous; cal small, 5-toothed; cor rotate, 5-lobed; anthers and filaments united into a column; ovary unilocular, with 1 suspended ovule; stigmas 3; fr dry, indehiscent, not inflated, covered by prickly bristles; annual vines with branched tendrils, broad, angular or lobed lvs, and small, white of greenish fls, the pistillate in small capitate clusters, the staminate in corymbiform racemes. 15, mainly trop.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.