高山杜鹃 gao shan du juan

Azalea lapponica Linnaeus, Sp. Pl. 1: 151. 1753; A. ferruginosa Pallas; A. parvifolia (Adams) Kuntze; Rhododendron confertissimum Nakai; R. lapponicum subsp. parvifolium (Adams) T. Yamazaki; R. palustre Turczaninow ex de Candolle (1839), not Kron & Judd (1990); R. parvifolium Adams; R. parvifolium subsp. confertissimum (Nakai) A. P. Khokhrjakov.

Small, much-branched prostrate or erect shrubs, 0.2–0.45(–1) m tall. Petiole 1.5–4 mm, scaly; leaf blade oblong-elliptic, ovate-elliptic to oblong-obovate, 0.4–1.5(–2.5) × 0.2–0.5(–0.9) cm; base broadly cuneate; apex obtuse or rounded, mucronate; abaxial surface fawn to reddish brown, scales contiguous or overlapping, 2-colored, pale brown or ferruginous, nearly equal in number and intermixed; adaxial surface pale green, matt, densely scaly. Inflorescence (2–)3–5(–6)-flowered. Pedicel 0.3–1.2 cm, scaly; calyx reddish or purple; lobes (0.5–) 1–2 mm, deltoid or rounded, persistent in fruit, scaly, margin ciliate and rarely scaly; corolla broadly funnelform, violet rose to purple or rarely white, (0.65–)0.7–1.3(–1.6) cm, tube (1.5–) 2–5(–6) mm, outer surface glabrous, throat pubescent; stamens 5–10, filaments pubescent towards base; ovary ca. 1.2 mm, densely scaly; style 1.1–1.5 cm, longer than stamens, glabrous. Capsule cylindric-ovate, 3–6 mm, densely scaly. Fl. May–Jul, fr. Sep–Oct.

Arctic regions, mountain tundra, bogs, peat or moss lands, clayey soils, other damp places; sea level to 1900 m. Heilongjiang, Jilin, Liaoning, Nei Mongol [Japan, N Korea, Mongolia, Russia (Siberia); N Europe (Scandinavia), N North America (Canada, Greenland, N United States)].