Vines , twining or clambering. Stems green, apically tomentose grading to pilose or glabrate on older portions. Leaves not peltate. Leaf blade generally ovate to hastate or oblong, base cordate, truncate, or rounded, margins entire, apex mucronate; surfaces soft-pubescent or glabrous. Inflorescences axillary or terminal, racemes or racemose panicles; bracts minute (bracteoles). Flowers 3-ranked; sepals 6-9, ovate to elliptic or obovate, outer sepals glabrous or pilose to sparsely pilose abaxially, inner sepals glabrous; petals 6, free. Staminate flowers: petals to 2 mm, auriculate lobes at base inflexed over 6 stamens; filaments distinct; anthers 4-locular; pistillodes 36 or absent, glandular. Pistillate flowers: perianth similar to staminate; staminodes 6, poorly developed; pistils 6; ovary slightly asymmetrically pouched, glabrous; stigma entire. Drupes globose, glabrous; endocarp bony, depressed but not excavate, warty, ribbed. x = 13.
Sep, pet, and stamens each 6; pistils 3 or 6, with entire stigma; fr flattened on both sides, the stigmatic scar lateral; stone thickened and rough on the margin for three-fourths of its circumference, somewhat excavated on the sides; woody twiners. 10, warm reg.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.