苍白杜鹃 cang bai du juan

Rhododendron glaucophyllum Rehder var. tubiforme Cowan & Davidian, Rhododendron Year Book 3: 86. 1948; R. glaucophyllum subsp. tubiforme (Cowan & Davidian) D. G. Long.

Shrubs, evergreen, 0.3–2 m tall; stem and branches with smooth brown flaking bark. Petiole 4–13 mm, scaly; leaf blade leathery, aromatic, obovate, oblong-obovate, lanceolate to oblanceolate, 3.8–8 × 1–2.6 cm; base obtuse or tapering; apex obtuse or acute, mucronate; abaxial surface glaucous, scales 0.5–2(–3) × their own diameter apart, unequal, smaller pale yellow, larger brown, widely separated; adaxial surface dark green, shiny, scaly. Inflorescence 3–5(–10)-flowered. Pedicel 1–2 cm, scaly; calyx lobes 6–8(–10) mm, ovate-lanceolate or lanceolate, persisting to enclose mature capsule, scaly; corolla tubular-campanulate, pink to rose, with or without darker spots, 2–3(–3.8) cm, tube 6–11 mm; outer surface usually densely scaly; stamens 10, nearly as long as corolla, filaments densely pubescent in lower 1/2; ovary densely scaly; style slender, straight, nearly as long as corolla, glabrous. Capsule ovate, 5–8 mm, scaly. Fl. Apr–May, fr. Jun–Sep.

Mixed Rhododendron forests, bamboo forests, Rhododendron thickets, scrub, rocks; 3000–3600 m. SE Xizang [Bhutan, India].