云南杜鹃 yun nan du juan

Rhododendron aechmophyllum I. B. Balfour & Forrest; R. chartophyllum Franchet; R. chartophyllum f. praecox Diels; R. hormophorum I. B. Balfour & Forrest; R. shaanxiense W. P. Fang & Z. J. Zhao; R. suberosum I. B. Balfour & Forrest.

Shrubs, rarely small trees, deciduous, semievergreen or evergreen, 1–2(–4) m tall; old branches glabrous; young shoots sparsely scaly, otherwise glabrous or pubescent. Petiole 3–7 mm, sparsely scaly, pubescent or sometimes hispid; leaf blade oblong, lanceolate, oblong-lanceolate or obovate, 2.5–7 × 0.8–3 cm; base narrow to cuneate; apex acuminate or acute, apiculate; abaxial surface green or gray green, scales 2–6 × their own diameter unequal; adaxial surface not or sparsely scaly, sometimes pubescent along midrib. Inflorescence terminal or subterminal, shortly racemose or umbellate, 3–6-flowered; rachis 2–3 mm. Pedicel 0.5–2(–3) cm, not or sparsely scaly; calyx rimlike or 5-lobed, 0.5–1 mm, scaly or not; corolla broadly funnelform-campanulate, white, pale red or pale purplish, inside with red, brownish red, yellow or yellowish green spots, 1.8–3.5 cm, outer surface sparsely scaly or not; stamens unequal, long ones longer than corolla; filaments ± pubescent below; ovary 5-locular, densely scaly; style longer than corolla, glabrous. Capsule cylindric, 6–20 mm. Fl. Apr–Jun.

Mixed forests on slopes, Abies-Picea or Pinus-Quercus forest margins, thickets; (1600–)2200–3600(–4000) m. W Guizhou, S Shaanxi, W Sichuan, Xizang, Yunnan [Myanmar].