Rubus trijugus Focke

Shrubs to 2 m tall. Branches purplish red or purplish brown, cylindric, soft hairy when young, gradually glabrescent, glaucous, with sparse prickles. Leaves imparipinnate, (5–)7–9-foliolate; petiole 5–11 cm, petiolule of terminal leaflet 1–2 cm, lateral leaflets subsessile, petiolules and rachis with soft hairs and needle-like prickles; stipules linear, 4–7 mm, soft hairy; blade of leaflets ovate or ovate-elliptic, 2–5 × 1.5–4 cm, abaxially gray tomentose, adaxially appressed pubescent, base broadly cuneate or rounded, sometimes subtruncate on terminal leaflet, margin usually incised-doubly serrate, apex acute, sometimes acuminate on terminal leaflet. Inflorescences terminal corymbs or flowers in clusters of 3 or 4 at apex of branchlets, rarely flowers solitary in leaf axils; bracts linear, 3–6 mm, soft hairy. Pedicel 1–2(–3) cm, pubescent, with sparse, minute prickles. Flowers 1.5–2 cm in diam. Calyx abaxially pubescent; sepals erect, spreading, rarely reflexed in fruit, triangular-lanceolate or ovate-lanceolate, 1–1.4 cm × 4–6 mm, margin tomentose, apex caudate. Petals nearly erect, white, elliptic or oblong, shorter than or rarely as long as sepals, base clawed and pubescent. Stamens numerous, shorter than petals; base of filaments slightly broadened, flattened. Pistils many, slightly longer than stamens; ovary and base of style densely gray tomentose. Aggregate fruit red, subglobose, ca. 1 cm in diam., densely gray tomentose. Fl. May–Jun, fr. Jul–Aug.

Sichuan, Xizang, Yunnan.

Low slopes, mixed forests and forest margins in mountainous regions, grasslands, stream sides; 2500--3500 m.

Rubus trijugus là loài thực vật có hoa trong họ Hoa hồng. Loài này được Focke miêu tả khoa học đầu tiên năm 1911.

三对叶悬钩子（学名：Rubus trijugus），为蔷薇科悬钩子属下的一个植物种。