Herbs. Stems annual, climbing, branching, to 2.5 m, herbaceous, glabrous; prickles absent. Leaves evenly distributed; petiole ± equaling blade; tendrils numerous, long, functional; blade lustrous, dark green abaxially, narrowly to broadly ovate, 8-16 × 3.5-9 cm, often with minute, whitish pubescence abaxially mostly on veins, with transparent trichomes, base cordate, margins entire, convex, apex long-acuminate; leaves on branches with oblong, smaller blade. Umbels numerous, axillary to leaves, 10-35-flowered, globose; peduncle equaling or shorter than subtending leaf. Flowers: perianth greenish; tepals 3.5-5 mm; anthers shorter than filaments, ovules (1-)2 per locule; pedicel 0.5-2.2 cm. Berries black, subglobose, 8-10 mm, not glaucous. 2n = 26. Flowering Apr--Jun. Rich woods, thickets, usually in calcareous soils; 0--900 m; Ark., Del., D.C., Ill., Ind., Ky., Md., Minn., Mo., Nebr., N.J., N.Y., N.C., Pa., Tenn., Va., W.Va. The distribution of Smilax pulverulenta is disjunct. The eastern distribution is centered in the mid-Atlantic United States, while the western distribution is centered in the Ozark Plateau of Missouri.
Perennial herbaceous vine to 2.5 m tall Stem: climbing, branching, hairless, lacking prickles, with bracts near base. Leaves: alternate, numerous, stalked, shiny dark green beneath, 8 - 16 cm long, 3.5 - 9 cm wide, narrow to broad egg-shaped with a heart-shaped base and pointed tip, margins convex, typically with five major veins, often with tiny whitish hairs on veins beneath. The leaves of branches are smaller and oblong. Flowers: either male or female, found on separate plants (dioecious), borne on an inflorescence with branches radiating from a common point (umbel). The many umbels are borne axillary to the leaves, each being hemispherical to spherical and having ten to 35 flowers with six greenish tepals 3.5 - 5 mm long. Fruit: a black berry, 8 - 10 mm long, nearly spherical, with three to six seeds. Tendrils: many, borne in leaf axils, long.
Similar species: Smilax ecirrhata, Smilax illinoensis, Smilax herbacea, Smilax lasioneura, and Smilax pulverulenta are herbs without prickles. Smilax ecirrhata and S. illinoensis are erect, shorter than 1 m, and have zero to few tendrils and few umbels. Smilax herbacea leaves are hairless beneath, and S. lasionera leaves are dull pale green and hairy beneath.
Flowering: April to June
Habitat and ecology: Rare in rich woods, thickets, and edges of fields.
Occurence in the Chicago region: native
Etymology: Smilax is the ancient Greek name of an evergreen oak. Pulverulenta means powdery, referring to its fine hairs.