无柄杜鹃 wu bing du juan

Shrubs or small trees, 1.5–6 m tall; young shoots slightly gray-brown tomentose. Leaf blade leathery, oblong-elliptic to broadly oblanceolate or obovate, 10–33 × 4–10 cm; base rounded, with broad wings decurrent into petiole; apex acute; abaxial surface silvery-white to brownish, indumentum thin, compacted and agglutinated; adaxial surface glabrous. Inflorescence a lax short racemose umbel, 12–15-flowered; rachis ca. 10 mm, gray-white pubescent. Pedicel 1.5–3 cm, sparsely floccose, glabrescent; calyx irregular; lobes 7, 1–2 mm; corolla broadly campanulate, white slightly pink tinged with crimson blotch at base, 3.5–4 cm, lobes 7; stamens 14, unequal, filaments puberulent in lower part; ovary glabrous; style ± as long as corolla, glabrous, stigma capitate. Capsule oblong-cylindric, slightly curved, 3–4 × 5–7 mm. Fl. May–Jun, fr. Jul–Sep.

Open forests; 2500–3000 m. S Gansu, W Sichuan.