锈红杜鹃 xiu hong du juan

Rhododendron bureavioides I. B. Balfour; R. cruentum H. Léveillé.

Shrubs, 1–4 m tall; young shoots densely rusty-red to tawny woolly-tomentose, sometimes mixed with red-glands. Petiole 10–20 mm, rust-red woolly-tomentose; leaf blade leathery, elliptic to obovate-oblong, 6–14 × 2.5–5 cm; base obtuse or subrounded; apex acute or acuminate, apiculate; abaxial surface rust-red to tawny, densely woolly, hairs branched; adaxial surface shiny, glabrous. Inflorescence racemose-umbellate, 10–20-flowered; rachis and pedicels densely rust-red woolly-tomentose, hairs branched, and with glandular hairs. Pedicel 1.5–2 cm; calyx lobes 5, 5–10 mm, oblong, pubescent and glandular on lower half outside, margin glandular-ciliate; corolla tubular-campanulate or campanulate, white flushed pink to pink, with purple dots inside, 3–4.5 cm, lobes 5; stamens 10, unequal, filaments pubescent at base; ovary ovoid, 4–5 mm, densely glandular-hairy and long-hairy, sometimes glandular only; style ca. 3 cm, similarly glandular-hairy and hairy. Capsule oblong-cylindric, 15–20 × ca. 10 mm, with vestiges of glands and hairs. Fl. May–Jun, fr. Aug–Oct.

Coniferous forests, Rhododendron thickets, mountain slopes; 2800–4500 m. W Sichuan, N Yunnan.

Field observations suggest that Rhododendron bureavioides should be treated as a distinct species. It differs in having a bistrate indumentum.