《中国植物志》|| 杜鹃花科 ERICACEAE ||朱砂杜鹃亚组 Subsect. Cinnabarina (Hutch.) Sleumer ||朱砂杜鹃 Rhododendron cinnabarinum Hook.f.

117．朱砂杜鹃（中国高等植物图鉴）
Rhododendron cinnabarinum Hook. f. Rhodod. Sikkim Himal, t. 8. 1849; Hutch. in Stevenson, Spec. Rhodod. 222. 1930.; Hara, Fl. East. Himal. 238. 1966;中国高等植物图鉴3: 46. 图4045. 1974; Cullen in Not. Bot. Gard. Edinb. 39: 123. 1980; Davidian, Rhodod. Spec. 1: 108. t. 9. 1982; 西藏植物志3: 646. 1986.
常绿灌木，高1-3（-5）米。幼枝带紫色，散生鳞片。叶革质，椭圆形、长圆状椭圆形至长圆状披针形，顶端钝圆至锐尖，有短尖头，基部圆形或宽楔形，长3-6（-9）厘米，宽1.5-2.5（-5）厘米，上面常为灰绿色，无鳞片，下面灰白色，密被鳞片，鳞片小，不等大，相距等于其直径或近邻接；叶柄长0.5-2厘米。花序顶生，伞形，常具花2－4朵；花梗长0.5-1厘米，通常下弯；花萼小，长1-2毫米，波状5裂，外面和边缘有或无鳞片；花冠筒状，向上稍扩大而呈狭钟状，长2.5-3.8厘米，常为朱砂红色，5裂至上部1/3，裂片开展，顶端圆或钝尖；雄蕊10，不等长，稍短于花冠，花丝下部被疏柔毛；花柱基部被疏柔毛，稀无毛。蒴果长圆形或长圆状卵形，长约1厘米，密被鳞片；果梗短，弯曲或下弯。花期5月，果期9月。
产西藏东南部。生于山坡灌丛、竹林、冷杉、杜鹃林或松林中及河谷针叶-阔叶混交林下，海拔1 900-4 000米。尼泊尔、锡金、不丹也有。

《Flora of China》|| Apiaceae || Rhododendron ||朱砂杜鹃 Rhododendron cinnabarinum

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].