[*] Leaves ovate or roundish, etc., most of them rounded or heart-shaped at base, and 5–9-nerved, the three middle nerves or ribs stronger and more conspicuous.
[+] Peduncles shorter or scarcely longer than the petioles (2–6´´), flattened; leaves thickish, green both sides.
4. S. Wálteri, Pursh. Stem low, somewhat angled, prickly near the base or unarmed; leaves ovate to ovate-lanceolate or oblong, somewhat heart-shaped or rounded at base (3–4´ long); berries coral-red.—Pine barrens, N. J. to Fla.
5. S. rotundifòlia, L. (Common Greenbrier. Horse-brier.) Stem armed with scattered prickles, as well as the terete branches; branchlets more or less 4-angular; leaves ovate or round-ovate, often broader than long, slightly heart-shaped, abruptly short-pointed (2–3´ long); berries blue-black, with a bloom.—Moist thickets, N. Eng. to Ga., west to Minn. and Tex. Very variable, passing into var. quadrangulàris, Gray, which has branches, and especially branchlets, 4-angular, and is more common west.
[+][+] Peduncle longer than but seldom twice the length of the short petiole, flattened; leaves tardily deciduous or partly persistent; berries black, with a bloom.
6. S. glaùca, Walt. Terete branches and somewhat 4-angular branchlets armed with scattered stout prickles, or naked; leaves ovate, rarely subcordate, glaucous beneath and sometimes also above, as well as the branchlets when young (about 2´ long), abruptly mucronate, the edges smooth and naked.—Dry thickets, E. Mass. to Fla., west to S. Ind., Mo., and Tex.
7. S. bòna-nox, L. Branches and the angular (often square) branchlets sparsely armed with short rigid prickles; leaves varying from round-heart-shaped and slightly contracted above the dilated base to fiddle-shaped and halberd-shaped or 3-lobed, green and shining both sides, cuspidate-pointed, the margins often somewhat bristly-ciliate or spinulose. (S. tamnoides, Man.; probably not L.)—Thickets; Nantucket, Mass. (L. L. Dame); N. J. to Fla., west to Ill., Mo., and Tex.
[+][+][+] Peduncle 2–4 times the length of the petiole; leaves ample (3–5´ long), thin or thinnish, green both sides; berries black; stem terete and branchlets nearly so.
8. S. híspida, Muhl. Rootstock cylindrical, elongated; stem (climbing high) below densely beset with long and weak blackish bristly prickles, the flowering branchlets mostly naked; leaves ovate and the larger heart-shaped, pointed, slightly rough-margined, membranaceous and deciduous; peduncles 1½–2´ long; sepals lanceolate, almost 3´´ long.—Moist thickets, Conn. to Va., west to Minn. and Tex. June.
9. S. Pseùdo-Chìna, L. Rootstock tuberous; stems and branches unarmed, or with very few weak prickles; leaves ovate-heart-shaped, or on the branchlets ovate-oblong, cuspidate-pointed, often rough-ciliate, becoming firm in texture; peduncles flat (2–3´ long).—Dry or sandy soil, N. J. to Fla., west to S. Ind. and Mo. July.