414. Rhododendron exasperatum Tagg in J. B. Stevenson, Sp. Rhodod. 836. 1930.
粗糙叶杜鹃 cu cao ye du juan
Shrubs or small trees, 2–5 m tall; young shoots ca. 7 mm in diam. below inflorescence, densely glandular-setose. Petiole short and stout, 10–15 mm, usually setose, occasionally without setae; leaf blade leathery, broadly ovate or subobovate, 10–18 × 4–10 cm; base rounded; margin with caducous setae; apex rounded, acuminate; abaxial surface greenish, sparse brownish glandular-hairy, midrib setose, mainly at base; adaxial surface deep green, nearly smooth, with scattered setae, base of midrib with or without brownish setae; midrib narrow, raised abaxially, impressed adaxially; lateral veins 12–15-paired, slightly raised abaxially, slightly impressed adaxially, net veins inconspicuous. Inflorescence densely umbellate, 10–15-flowered; rachis ca. 5 mm. Pedicel 1(–1.5) cm, slightly glandular; calyx lobes 5, 4–5 mm, subovate, glabrous; corolla tubular-campanulate, fleshy, deep red, 3.5–4.5 × ca. 3.5 cm, with small deep red nectar pouches at base, glabrous inside; lobes 5, slightly unequal, ca. 1 × 1.8 cm, apex emarginate; stamens 10, unequal, 1.3–2.2 cm, filaments glabrous; anthers oblong, brown, 1.6–2 × 1–1.2 mm; ovary broadly cone-shaped, apex truncate, ca. 6 × 3 mm, densely glandular-hairy; style slender, ca. 2.2 cm, glabrous, stigma flattened, truncate, ca. 1 mm wide. Young fruits with dense persistent hair bases; calyx persistent.
Abies forests, Rhododendron thickets; 3000–3600 m. SE Xizang [India, Myanmar].