107. Rhododendron orthocladum I. B. Balfour & Forrest, Notes Roy. Bot. Gard. Edinburgh. 11: 104. 1919.
直枝杜鹃 zhi zhi du juan
Erect much-branched shrubs, (0.5–)1(–1.3) m tall; branchlets densely brown scaly. Petiole 0.8–2.5(–3) mm, scaly; leaf blade narrowly elliptic, lanceolate to linear-lanceolate, (0.5–) 0.8–1.6(–2) × (0.1–)0.25–0.5(–0.6) cm; base cuneate or obtuse; apex obtuse, shortly or obscurely mucronate; abaxial surface yellowish brown to fawn, scales contiguous or almost so, golden to yellow brown, with few to many deeper brown scales intermixed; adaxial surface gray-green, scales dense, pale, translucent. Inflorescence (1–)2–4-flowered. Pedicel 0.15–0.2(–0.3) cm, scaly; calyx reddish, lobes usually unequal, 0.5–1.5 mm, triangular to rounded, scaly at base, margin occasionally with a few scales and cilia; corolla funnelform, pale to deep lavender-blue or deep purple, rarely whitish pink, 0.7–1.4 cm, tube 2–5 mm, outer surface not or only sparsely scaly, throat pubescent; stamens (8–)10(–11), shorter than to equaling corolla, filaments villous towards base; ovary (1–)2(–3) mm; style 0.35–0.5 cm or 1.5–1.6 cm, scales sparse or absent. Capsule ovoid, 2–5 mm, scaly. Fl. May–Jun, fr. Jul–Aug.
Forest margins, thickets, alpine slopes, cliffs; 2500–4500 m. SW Sichuan, N Yunnan.