Herbs. Stems annual, erect to ascending, branched, 2-2.5 m, herbaceous, glabrous; prickles absent. Leaves evenly distributed, proximalmost smaller, narrower; petiole 1.5-9 cm, shorter than blade; tendrils numerous, long, functional; blade not lustrous, pale green abaxially, ovate to round, 4-8 × 3-6 cm, not glaucous, pubescent abaxially, with transparent trichomes, base cordate, margins entire, convex, apex acuminate to rounded and cuspidate. Umbels many, axillary to leaves, to 35-flowered, dense, globose; peduncle to 12+ cm, short. Flowers: perianth greenish; tepals 3.5-4.5 mm; anthers equaling or shorter than filaments; ovules (1-)2 per locule; pedicel 0.5-1.5 cm. Berries bluish black to black, subglobose, 8-10 mm, glaucous. 2n = 26. Flowering May--Jun. Rich, alluvial woods, thickets, borders; 300--700 m; Man., Ont., Sask.; Ala., Ark., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Mich., Minn., Miss., Mo., Mont., Nebr., N.Y., N.Dak., Ohio, Okla., Pa., S.Dak., Tenn., Tex., Wis., Wyo. Smilax lasioneura is primarily distributed in the central plains and lower elevations of the Appalachian and Rocky mountains. Plants distributed in the southern humid areas tend to be larger than those of more northern areas.
Perennial herbaceous vine 2 - 2.5 m tall Stem: erect to ascending, branched, hairless, lacking prickles, with spreading-ascending bracts near base. Leaves: alternate, numerous, stalked, 4 - 8 cm long, 3 - 6 cm wide, the lower leaves smaller and narrower, egg-shaped to round with a heart-shaped base and a pointed to rounded tip often having an abrupt point (cusp), margins convex, minutely hairy and paler beneath. Flowers: either male or female, found on separate plants (dioecious), borne on an inflorescence with branches radiating from a common point (umbel). The many dense umbels are borne axillary to the leaves, each being spherical and having up to 35 flowers with six greenish tepals 3.5 - 5 cm long. Fruit: a bluish black to black berry, 8 - 10 mm long, nearly spherical, covered with a whitish waxy coating (glaucous), containing three to six seeds. Tendrils: numerous, borne in leaf axils.
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. pulverulenta leaves are shiny dark green and hairy beneath.
Flowering: early May to late June
Habitat and ecology: Frequent in woods, shaded dune slopes, clearings, old pastures, fencerows, roadsides and other open areas.
Occurence in the Chicago region: native
Etymology: Smilax is the ancient Greek name of an evergreen oak. Lasioneura means "hairy-nerved."