Description from Flora of China
Shrubs lianoid, semideciduous, to 3 m tall. Branchlets brown or reddish brown, terete, thinly pubescent or subglabrous, with sparse, curved minute prickles. Leaves simple; petiole 2–4(–5) cm, thinly pubescent or subglabrous, with sparse, minute prickles; stipules caducous, free, to 1 cm, laciniate-parted nearly to base, lobes linear to lanceolate, thinly pubescent or subglabrous; blade broadly ovate, rarely oblong-ovate, 5–10(–12) × 4–8 cm, 5-veined, abaxially pilose, more densely so along veins, rarely glabrous, with sparse, minute prickles along midvein, adaxially pilose or hairy only along veins, base cordate, margin distinctly 3–5-lobed or undulate, serrulate, apex acuminate. Inflorescences terminal or axillary, terminal ones usually cymose panicles, 10–15 cm, axillary ones often subracemes, shorter, sometimes flowers few in clusters in leaf axils; rachis and pedicels thinly pubescent, subglabrous, or glabrous; bracts 6–9 mm, margin laciniate lobed; lobes linear, puberulous. Pedicel 5–10 mm. Flowers 7–9 mm in diam. Calyx abaxially thinly pubescent; sepals ovate-lanceolate or triangular-lanceolate, 5–8 × 2.5–4 mm, margin entire, apex acuminate, margin of inner sepals gray tomentose. Petals white, obovate, glabrous, slightly shorter than or nearly as long as sepals, base clawed. Stamens many, somewhat shorter than petals; filaments broad, complanate. Pistils ca. 15–20, slightly shorter than or ca. as long as stamens, glabrous. Aggregate fruit red at maturity, subglobose, 6–8 mm in diam., glabrous, with many drupelets; pyrenes small, ca. 2 mm, prominently rugose. Fl. Jul–Aug, fr. Sep–Nov. 2n = 28.
Rubus urophyllus Y. C. Liu & F. Y. Lu (Quart. J. Chin. Forest. 9(2): 133. 1976) was treated in Fl. Taiwan is an uncertain species that might be only varietally distinct from R. lambertianus.
Slopes, roadsides, montane valleys, stony ravines, grasslands, thickets, sparse forests, forest margins, moist places; 200--2500 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Sichuan, Taiwan, Yunnan, Zhejiang [Japan, Thailand].