Shrubs scandent, to 5 m tall, with arching or climbing branches. Branchlets brown or reddish brown, densely spreading straight tomentose-villous, with sparse, recurved prickles to 5 mm; petiole 3–4.5 cm, yellowish gray to rust colored tomentose-villous, with sparse, minute prickles; stipules oblong to orbicular, 1–1.5(–2) cm, margin deeply digitately or pinnately divided, lobes linear or linear-lanceolate, hairy; blade suborbicular or broadly ovate, 6–16 × 5–14 cm, usually palmately 5-veined, thinly leathery, abaxially yellowish gray to rust colored tomentose, villous along veins, adaxially sparsely villous and distinctly bullate between veins, base cordate with basal incision to 3 or 4 cm deep, margin shallowly 5–7-lobed; lobes apically obtuse or acute, unevenly coarsely serrate. Inflorescences terminal, narrow cymose panicles or subracemes, 6–11 cm, sometimes flowers few in axillary clusters, rarely flowers solitary; rachis and pedicels tomentose-villous, with minute recurved prickles; bracts 1–1.4 cm, pinnatifid to pinnatipartite; lobes linear or lanceolate. Pedicel 5–10(–15) mm. Flowers 1–1.6 cm in diam. Calyx abaxially tomentose-villous; tube cupular; sepals broadly ovate to triangular-ovate, 6–9 × 5–8 mm, apex and margin of outer sepals palmately or pinnately laciniate, rarely undivided, inner sepals entire, shortly pointed, abaxially tomentose, intermixed villous. Petals white, suborbicular to broadly obovate, 5–9 × 4–9 mm, base clawed. Stamens many, shorter than petals; filaments to 5 mm, broad, complanate; anthers with few long hairs. Pistils numerous, longer than stamens; ovary and style glabrous. Aggregate fruit red, subglobose, to 1.8 cm in diam.; pyrenes rugose. Fl. Jul–Sep. fr. Oct–Nov. 2n = 42*.
Rubus alceifolius var. diversilobatus (Merrill & Chun) T. T. Yü & L. T. Lu; R. bullatifolius Merrill; R. fimbriiferus Focke; R. fimbriiferus var. diversilobatus Merrill & Chun; R. gilvus Focke; R. hainanensis Focke; R. laciniatostipulatus Hayata ex Koidzumi; R. monguillonii H. Léveillé & Vaniot; R. multibracteatus H. Léveillé & Vaniot var. demangei H. Léveillé.
Isotype for Rubus bullatifolius Merr. Catalog Number: US 1514964 Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany Verification Degree: Card file verified by examination of alleged type specimen Preparation: Pressed specimen Collector(s): J. F. Rock Year Collected: 1922 Locality: Border of Yunnan, between Tengyueh and Bhamo., China / Myanmar, Asia-Temperate / Asia-Tropical