138. Rhododendron leucaspis Tagg, Gard. Chron. 85: 308. 1929.
白背杜鹃 bai bei du juan
Dwarf shrubs, erect, straggly, evergreen, sometimes epiphytic, 0.3–0.6(–1) m tall; branchlets scaly, setose. Petiole 4–9 mm, scaly, setose; leaf blade leathery, broadly elliptic to obovate, 3–6 × 1.5–3 cm; base cuneate; apex obtuse, mucronate; abaxial surface glaucous, scales 0.5–1 × their own diameter apart, varying in size, brown, bladderlike, sunk in pits; adaxial surface and margin sparsely setose. Inflorescence 1–2(–3)-flowered. Pedicel 0.6–1 cm, scaly, usually not setose; calyx greenish often also reddish; lobes (6–)7–8 mm, obovate to rounded, persisting to enclose mature capsule, scaly, ciliate; corolla rotate or saucer-shaped, white, often tinged pinkish, 2.5–3.2 cm, tube 8–12 mm, outer surface scaly, inner surface pilose; stamens 10, filaments pubescent towards base or for 3/4 of their length; ovary densely scaly; style stout, sharply bent, short, scaly at base. Capsule ovoid to cylindric-ovoid, 8–10 mm, scaly. Fl. Apr–Jun, fr. Jun–Aug.
Thickets, scrub, slopes, grassy places, cliffs; 2100–3300 m. S Xizang.