Vines; rhizomes knotty, short. Stems perennial, climbing, branching, terete, to 7+ m × 9 mm, woody, glabrous, with prickles proximally, prickles usually absent distally; prickles blackish, unequal, 3-10+ mm, bristly, flexible. Leaves ± persistent in southern part of range, deciduous in north; petiole 1-2 cm; blade green, drying to light olive-gray, ovate-lanceolate, ovate, or sometimes pandurate, prominently reticulate, thin, 5-13 × 3-10 cm, not glaucous, glabrous (to prickly on major veins abaxially), base rounded to cordate, margins entire apically, minutely serrulate basally, thin, flat, not banded, not lobed, apex pointed. Umbels many, axillary to leaves, to 25-flowered, open to dense, spherical; peduncle often drooping, 1.5-6.5 cm. Flowers: perianth green to bronze; tepals 4-5 mm; anthers ± equaling to shorter than filaments; ovule 1 per locule; pedicel 0.4-1.2 cm. Berries black, globose, 6-10 mm, not glaucous. Flowering May--Jun. Wet to dry woods, thickets, bottomlands; 0--400 m; Ont.; Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., S.C., S.Dak., Tenn., Tex., Vt., Va., W.Va., Wis. Smilax tamnoides is marked by its dark, flexible, and unequal bristles and leaves with minutely serrulate margins basally. The far-western S. californica appears to be closely related but lacks the serrulate margins of the leaf bases.
Slender woody vine, often climbing high, beset (at least below) with unequal needle-like prickles; lvs deciduous, shiny-green, ovate to rotund; 8-12 נ6-10 cm at maturity; acute to rounded or cuspidate; at base rounded to truncate or cordate, not thickened at the margin, minutely serrulate (visibly so at 10ש, 5- or 7-nerved, the reticulate veinlets not much elevated; peduncles flattened, mostly 2-6 cm, generally at least twice as long as the subtending petiole; fr black, not glaucous, 6-8 mm, with 1(2) seeds; 2n=32. Moist woods and thickets; Conn. and N.Y. to n. Fla., w. to Mich., s. Minn., Nebr., and Tex., the commonest greenbrier in the w. part of our range. May, June. (S. pseudochina, misapplied; S. tamnoides, perhaps misapplied)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.