管花杜鹃 guan hua du juan

Rhododendron keysii var. unicolor Hutchinson.

Erect shrubs, evergreen, rarely epiphytic, 1–4(–6) m tall; branches slender, straggling. Petiole 5–16 mm, scaly; leaf blade leathery, lanceolate-elliptic or lanceolate-oblong, (3–)4–8(–15) × 1–3(–4) cm; base cuneate; apex acute; abaxial surface pale green, scales less than 1 × their own diameter apart, unequal, dark brown to brown, broadly rimmed; adaxial surface dark green, shiny, scales dense, brown, 1–3 × their own diameter apart. Inflorescence usually axillary, shortly racemose, (2–)4–6-flowered; flowers pendulous. Pedicel slender, 0.4–0.8 cm, sparsely scaly; calyx lobes ca. 1 mm, shortly ovate, scaly, margin ciliate; corolla tubular, slightly ventricose, orange or salmon pink to deep red, (1.4–)1.8–2.5 cm; lobes erect, oblong, small; stamens 10, filaments densely pubescent proximally; style usually pubescent proximally. Capsule cylindric, 8–10 mm, densely scaly. Fl. Jun–Jul, fr. Oct.

Forests, thickets; 2400–4300 m. S Xizang [Bhutan, NE India, Sikkim].