Shrubs climbing, to 2 m tall, long stoloniferous. Branches grayish brown to dark reddish brown, glabrous, with sparse, somewhat curved prickles or nearly unarmed. Leaves simple; petiole 1–4 cm, shortly petiolate at bases of inflorescences, glabrous, with sparse, slightly curved prickles; stipules caducous, free, oblong or liguliform, 1–1.4 cm, glabrous or subglabrous, apex divided; blade broadly ovate, rarely ovate-oblong, 9–12 × 6–9 cm, palmately veined from base, abaxially densely gray tomentose, adaxially glabrous, base rounded to shallowly cordate, margin irregularly coarsely sharply serrate, apex shortly caudate. Inflorescences terminal, cymose panicles, much branched, pyramidal, to 10–22 cm; rachis and pedicels tomentose; bracts oblong or liguliform, rarely ovate, 1–1.2 cm, tomentose, apex divided. Pedicel 0.7–1.5 cm. Flowers 6–8 mm in diam. Calyx purple, abaxially densely gray tomentose; tube shorter, shallowly pelviform; sepals erect or reflexed after anthesis, ovate or ovate-lanceolate, 4–6(–7) × 2–3 mm, margin entire, rarely with 2 or 3 teeth, apex acuminate. Petals usually absent. Stamens many, in 1 whorl, shorter than sepals; filaments linear, glabrous. Pistils slightly shorter than stamens, glabrous. Aggregate fruit black at maturity, subglobose, less than 1 cm in diam., glabrous. Fl. Jun–Jul, fr. Aug–Sep.