Description from Flora of China
Rubus tagallus Chamisso & Schlechtendal var. lanyuensis (Chang) S. S. Ying.
Shrubs erect. Branches glabrous, with short prickles. Leaves imparipinnate, usually 3–5-foliolate; petiole 3–4 cm, sparsely villous, prickly; stipules linear-lanceolate, 0.8–1.2 cm, sparsely pilose; blade of leaflets ovate, 3–5 × 3–4 cm, veins raised abaxially, impressed adaxially, both surfaces glabrous or nearly so except sparsely villous at base, abaxially glandular, base cuneate to rounded, margin doubly serrate, apex acute. Inflorescences axillary racemes, few flowered. Pedicel 1–1.5 cm, glabrous. Flowers ca. 2 cm in diam. Calyx abaxially glabrous, glandular; tube cupular, 1.5–1.8 cm in diam.; sepals narrowly triangular, ca. 8 mm, apex shortly caudate. Petals white, orbicular-ovate, 6–7 mm. Filaments glabrous. Apex of ovary with few hairs. Fruit unknown.
Near sea level. Taiwan (Lan Yu).