Sp. Pl. 1: 340. 175.
Gen. Pl. ed. 5, 158. 1754.
Vines, twining, or lianas. Stems green, apically tomentose grading to glabrate on older portions. Leaves peltate, petiole inserted near margin, rarely with petiole attached basally. Leaf blade broadly ovate, generally (3-)5-7-lobed or angled, base cordate, truncate, or rounded, margins entire, apex acuminate to rounded, mucronate, rarely notched or obcordate; surfaces abaxially very pale, sometimes silvery, glabrous to pilose, adaxially glabrous to sparsely pilose. Inflorescences axillary, panicles well developed; bracts minute (bracteoles). Flowers 3-ranked; sepals usually 6, ovate to elliptic or obovate, glabrous; petals (4-)6(-12), free, to 4 mm, entire, auriculate basal lobes absent. Staminate flowers: petals entire; stamens 12-36; filaments distinct; anthers 4-locular; pistillodes absent. Pistillate flowers: staminodes 6-9, well developed; pistils (2-)3(-4); ovary slightly asymmetrically pouched, glabrous; stigma slightly lobed. Drupes globose, glabrous; endocarp bony, warty, ribbed.
North America, Mexico, and Asia.
Species 3 (1 in the flora).