三棱枝白珠 san leng zhi bai zhu

Shrubs 1–2 m tall. Twigs distinctly trigonous or with narrow wings, glabrous. Leaves scattered; petiole 5–10 mm, glabrous; leaf blade elliptic or rhombic-elliptic, (4–)6–10 × 2.5–4 cm, thickly leathery, abaxially sparsely shortly brown glandular setose, adaxially glabrous, secondary veins 2 or 3 pairs, fine veins subparallel, raised abaxially, impressed adaxially, base cuneate, margin dentate, apex acute to acuminate. Inflorescences axillary, racemose, 2–3 cm, angled, 10-flowered, densely pubescent; bracts ovate-lanceolate, 5–6 mm, leathery, glabrous or abaxially puberulous, with 1 distinct main vein. Pedicel 2–4 mm, pubescent; bracteoles 2, apical, similar to bracts, ovate, ca. 3 mm. Calyx 2.5–3 mm, divided to near base; lobes triangular-lanceolate, glabrous. Corolla white, urceolate, ca. 5 mm, abaxially glabrous, adaxially pilose; lobes triangular-ovate, ca. 0.5 mm. Filaments ca. 0.5 mm, dilated below middle, papillate; anthers ca. 1.5 mm, thecae slenderly 2-awned. Ovary tomentose. Calyx at fruiting purple; capsule globose, 4–6 mm in diam. Fl. Oct, fr. Jun–Aug.

Forests, thickets on river terraces; 2000–2300 m. SE Xizang (Mêdog).