Vines forming extensive colonies; rhizomes irregularly branched, tuberous, woody. Stems perennial, climbing, branching, terete, 5+ m × 15 mm , woody, glaucous, glabrous; prickles dark, flat, to 12 mm, rigid. Leaves evergreen, ± evenly arranged; petiole 0.5-1.5 cm; blade abaxially green, drying to pale brown to brownish green, oblong-elliptic, lance-elliptic, or, sometimes, linear or broadly ovate, not prominently reticulate, 3-veined from base, 7-13 × 1.3-4(-6) cm, coriaceous, not glaucous, glabrous or minutely pubescent abaxially, base attenuate to rounded; margins entire, often revolute, teeth absent; apex acute to rounded, often mucronate. Umbels numerous, axillary to leaves, generally on short branches, 5-12(-25)-flowered, ± open, spherical; peduncle 0.5-1.5 cm, shorter than subtending leaf. Flowers: perianth yellow, cream, or white; tepals 4-5 mm; anthers exceeding filaments; ovule 1 per locule; pedicel 0.5-1 cm. Berries black, ovoid, 5-8 mm, shining, glaucous.
Slender woody vine, climbing high; stems glaucous at first, beset with numerous straight, stout prickles below, generally innocuous above; lvs evergreen, leathery, oblong or lanceolate to ovate, 6-10 cm, obtuse or subacute, entire, cuneate at base, 3-nerved, the outer nerves much nearer to the margin than to the midnerve; peduncles terete or angled, about equaling the subtending petioles; fr purple to black, mostly 1-seeded, ripening the second year; 2n=32. Wet woods and margins of swamps; N.J. to Fla. and Tex., and inland to e. Tenn. Aug., Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.