416. Rhododendron erosum Cowan, Notes Roy. Bot. Gard. Edinburgh. 19: 225. 1937.
啮蚀杜鹃 nie shi du juan
Shrubs or small trees, 4.5–6 m tall; bark grayish brown, flaking; branchlets ca. 4 mm in diam. below inflorescence; young shoots grayish white, densely glandular-hairy. Petiole stout, 7–12(–20) mm, densely brown glandular-setose; leaf blade leathery, broadly elliptic or oblong-elliptic to obovate, 8–10.5(–16.5) × (3–)3.7–4.5(–9) cm; base rounded or shallowly cordate; margin slightly reflexed; apex obtuse or broadly rounded, with small hard point; abaxial surface greenish, yellowish brown floccose-woolly or with gray to yellowish brown wool and glands; adaxial surface markedly bullate, green, brown floccose on base of midrib; midrib raised abaxially, impressed adaxially; lateral veins (10–)15–17-paired, deeply impressed adaxially. Inflorescence umbellate, 12–15-flowered; rachis ca. 15 mm, sparsely yellowish glandular-hairy. Pedicel 0.8–0.9 cm, with long glandular hairs; calyx cup-shaped; lobes 5, 5–5.2 mm, suborbicular, margin glandular-ciliate, ca. 4 mm; corolla tubular-campanulate, deep rose-red, 2.8–3.3 × 3.2–3.8 cm, base with 5 deep red nectar pouches, inner surface of tube white-puberulent; lobes 5, suborbicular, ca. 1.2 cm, apex deeply emarginate; stamens 10, unequal, 1.4–2.3 cm; filaments white, glabrous; anthers obovate, deep brown, ca. 1.3 mm; ovary oblong, ca. 5 mm, densely glandular; style white, ca. 2.1 cm, glabrous; stigma slightly lobed, ca. 1.6 mm wide. Capsule long-cylindric, 15–20 × ca. 6 mm. Fl. Apr–May, fr. Oct.
Coniferous forests, Betula and Rhododendron forests and thickets; 3000–3700 m. S Xizang.