白碗杜鹃 bai wan du juan

Rhododendron cordatum H. Léveillé.

Shrubs, 1.5–2 m tall; old branches grayish white, glabrous, bark sometimes flaking; young shoots greenish, with sparse red glands. Petiole terete, deep purplish green, 10–25 mm, glandular-hairy when young, glabrescent; leaf blade leathery, ovate to oblong-elliptic, 3.5–7.5 × 2–4.5 cm; base subcordate or suborbicular; apex rounded, apiculate; abaxial surface greenish or grayish green; adaxial surface deep green; midrib raised abaxially, flat adaxially; lateral veins 10–14 pairs, inconspicuous on both surfaces. Inflorescence racemose-umbellate, 5–7-flowered; rachis 5–10 mm, shortly glandular-hairy. Pedicel 1.5–3 cm, densely glandular; calyx membranous, lobes 5, 5–8 × 2–5 mm, unequal, ovate, outside sparsely glandular, margin shortly glandular-hairy; corolla campanulate, bowl-shaped or saucer-shaped, broad in the middle part, white or pink, 2.5–3.5 × 5–6 cm; lobes 5, suborbicular, ca. 1.5 × 2 cm, apex emarginate; stamens 10, unequal, 0.8–1.5 cm, filaments white, glabrous, anthers oblong, deep purplish red, 3–4 mm; ovary cone-shaped, 4–5 mm, usually densely purplish red glandular; style 1.5–2 cm, stigma capitate. Capsule cylindric, usually curved at maturity, 20–25 × 5–7 mm, glands persistent. Fl. Jun–Jul, fr. Aug–Sep.

Abies forests, scrub, mountain slopes; 3000–3800 m. SW Sichuan, E Xizang.