122. Rhododendron cinnabarinum J. D. Hooker, Rhododendr. Sikkim-Himalaya. 1: t. 8. 1849.
朱砂杜鹃 zhu sha du juan
Shrubs, often straggling, usually evergreen, rarely semideciduous, 1–3(–7) m tall. Petiole 5–20 mm, scaly; leaf blade leathery, narrowly to broadly elliptic, oblong-elliptic to oblong-lanceolate or ovate, 3–6(–11) × 1.5–2.5(–5) cm, more than 2.2 × as long as broad; base usually rounded; apex obtuse, mucronate; abaxial surface pale glaucous-green, scales 0.5–1 × their own diameter apart, or nearly contiguous, usually unequal, brown or brown-red, rather fleshy; adaxial surface grayish green, usually scaly. Inflorescence terminal, umbellate, 2–4(–7)-flowered. Pedicel 0.5–1(–1.6) cm; calyx discoid or undulate, 1–2 mm, usually scaly; corolla tubular to narrowly campanulate, variable in color: yellow to cinnabar red (sometimes 2-colored), deep plum crimson, or rarely plum purple, 2.5–3.8 cm, fleshy; lobes spreading, ca. 1/3 as long as corolla, without or rarely with scales abaxially; stamens 10, slightly shorter than corolla, filaments pubescent towards base, rarely glabrous; ovary scaly, apex sometimes puberulous; style sparsely pubescent towards base or glabrous. Capsule cylindric or cylindric-ovoid, ca. 10 mm, densely scaly. Fl. May, fr. Sep.
Forests, open woodlands, forest margins, Rhododendron thickets, among shrubs, hillsides; 1900–4000 m. S Xizang, NW Yunnan [Bhutan, NE India, NE Myanmar, Nepal, Sikkim].