牛皮杜鹃 niu pi du juan

Rhododendron chrysanthum Pallas; R. officinale Salisbury.

Dwarf shrubs, 0.1–1 m tall; stems horizontal with obliquely ascending branchlets; bud scales persistent. Petiole 5–10 mm, glabrous; leaf blade leathery, oblanceolate to obovate-oblong, 2.5–8 × 1–3.5 cm; base cuneate; apex obtuse or rounded, mucronate; both surfaces glabrous when mature, sometimes with vestiges of juvenile tomentum abaxially; reticulate veins distinct. Inflorescence corymbose, 5–8-flowered; rachis ca. 10 mm. Pedicel erect, ca. 3 cm, sparsely rufescent-hairy; calyx lobes 5, ca. 2 mm, floccose; corolla campanulate, yellow, with 1 upper lobe red-spotted, 2.5–3 cm; lobes 5, unequal; stamens 10, unequal, filaments pubescent at base; ovary ca. 5 mm, densely rufous-tomentose; style ca. 2.5 cm, glabrous, stigma small, 5-lobulate. Infructescence erect; peduncle 4.5–6 cm. Capsule oblong-cylindric, 5-valved, 10–14 × 5–6 mm. Fl. May–Jun, fr. Jul–Aug.

Grasslands, among bryophytes, alpine regions; 1000–2500 m. SE Jilin, Liaoning [Japan, Korea, Mongolia, Russia].