Flora of North America species comparison

biennial, creeping (often growing over other vegetation), sparsely to densely hairy, eglandular or sparsely to densely sessile- to stipitate-glandular, usually strongly pruinose;

prickles moderate to dense, erect to retrorse or hooked, weak to moderately stout, 4–10 mm, narrow- to broad-based.

biennial, erect, glabrescent, eglandular or stipitate-glandular, strongly pruinose;

prickles absent or sparse to dense, erect, weak, 1–4 mm, broad-based;

bristles present or absent.

deciduous or persistent, usually ternate, sometimes simple or pinnately compound;

stipules filiform to linear, 7–17 mm;

leaflets 3(–5), terminal ovate to lanceolate, 3.5–12 × 3–10 cm, base cuneate or rounded to cordate, shallowly sharp-lobed or unlobed, margins coarsely serrate to doubly serrate, apex acute to acuminate, abaxial surfaces with slender, erect prickles on larger veins, moderately to densely hairy, eglandular, rarely sparsely sessile-glandular along midvein.

deciduous, pinnately compound;

stipules filiform, 5–10 mm;

petiole unarmed or with prickles, strigose or glabrous, glandular or eglandular;

terminal leaflets petiolulate, lateral sessile or subsessile;

leaflets 3–5(–7), terminal ovate to lanceolate, 7–15 × 4–11 cm, base rounded to cordate, unlobed or 2-lobed, margins serrate to doubly serrate, apex acute to attenuate, abaxial surfaces unarmed or with prickles, strongly white-tomentose, eglandular or glandular.

terminal on short shoots, usually appearing axillary, 1–5-flowered, cymiform or racemiform.

terminal and axillary, (1–)3–7(–20)-flowered, racemiform.

prickles moderate to dense, erect, densely hairy, eglandular or sparsely to densely stipitate-glandular.

unarmed or prickles sparse, hooked, glabrous or sparsely pubescent, stipitate-glandular or eglandular.

usually functionally unisexual;

petals white, in staminate flowers ovate or obovate to narrowly elliptic, 7–18 mm, in pistillate ovate to elliptic, 6–11 mm;

filaments filiform;

ovaries glabrous or hairy.

bisexual;

petals white to greenish white, spatulate to obovate, 5–10 mm;

filaments filiform or slightly dilated basally;

ovaries pubescent.

black, sometimes red or purple, rarely white, not pruinose, globose to cylindric, 1–2.5 cm;

drupelets 20–50, strongly coherent, separating with torus attached.

usually red to whitish, rarely amber, globose to conic, 0.5–2 cm;

drupelets 10–60, coherent, separating from torus.

= 42, 56, 63, 70, 77, 84, 91.