《中国植物志》|| 杜鹃花科 ERICACEAE ||黄花杜鹃亚组 Subsect. Boothia (Hutch.) Sleumer ||白背杜鹃 Rhododendron leucaspis Tagg

132. 白背杜鹃（西藏植物志）
Rhododendron leucaspis Tagg in Gard. Chron. 85: 128, 135, 308. 1929; Hutch. in Stevenson, Spec. Rhodod. 164. 1930; Curtis's Bot. Mag. 164. t. 9665. 1944; Cowan et Davidian in R. H. S. Rhodod. Year Book, 3: 69. 1948; Cox, Dwarf Rhodod. 85. t. 10. 1973; Cullen in Not. Bot. Gard. Edinb. 39: 138. 1980; Davidian, Rhodod. Spec. 1: 75. 1982;西藏植物志3: 641. 1986;横断山区维管植物下册1440. 1994.
常绿小灌木，高30-60（-100 ）厘米；枝密集，直立或匍匐，有时附生。幼枝密被硬毛和鳞片。叶宽椭圆形至倒卵形，先端圆或钝，具小短尖头，基部楔形渐狭，长3-6厘米，宽1.5-3厘米，上面和边缘具疏硬毛，下面苍白色，密被鳞片，鳞片褐色，大小多变，大的较少，下陷，几泡状，相距为其直径或更近；叶柄长4-9毫米，被硬毛和疏鳞片。花序具1-2（3）花；花梗长6-10毫米，有鳞片，无硬毛或有时疏被短柔毛；花萼大，深5裂，裂片圆形至倒卵形，长6-8毫米，绿色或常带红色，基部有鳞片，或有时裂片外有鳞片，边缘密被睫毛；花冠辐状或几为盘状，长2.5-3.2厘米，白色，常带粉红色，花管长8-12毫米，外面有鳞片，无毛或疏被毛；雄蕊10，不等长，花丝下半部或3/4被毛；子房密被鳞片，花柱短，粗壮而强度弯弓，基部被鳞片。蒴果卵形或长圆状卵形，长8-10毫米，被鳞片，花萼宿存。
产西藏东南部（米林、察隅）。生于密茂的灌丛中或河谷草坡，海拔2 100-3 300米。模式标本为采自米林的种子栽培而得。

《Flora of China》|| Apiaceae || Rhododendron ||白背杜鹃 Rhododendron leucaspis

138. Rhododendron leucaspis Tagg, Gard. Chron. 85: 308. 1929.

白背杜鹃 bai bei du juan

Dwarf shrubs, erect, straggly, evergreen, sometimes epiphytic, 0.3–0.6(–1) m tall; branchlets scaly, setose. Petiole 4–9 mm, scaly, setose; leaf blade leathery, broadly elliptic to obovate, 3–6 × 1.5–3 cm; base cuneate; apex obtuse, mucronate; abaxial surface glaucous, scales 0.5–1 × their own diameter apart, varying in size, brown, bladderlike, sunk in pits; adaxial surface and margin sparsely setose. Inflorescence 1–2(–3)-flowered. Pedicel 0.6–1 cm, scaly, usually not setose; calyx greenish often also reddish; lobes (6–)7–8 mm, obovate to rounded, persisting to enclose mature capsule, scaly, ciliate; corolla rotate or saucer-shaped, white, often tinged pinkish, 2.5–3.2 cm, tube 8–12 mm, outer surface scaly, inner surface pilose; stamens 10, filaments pubescent towards base or for 3/4 of their length; ovary densely scaly; style stout, sharply bent, short, scaly at base. Capsule ovoid to cylindric-ovoid, 8–10 mm, scaly. Fl. Apr–Jun, fr. Jun–Aug.

Thickets, scrub, slopes, grassy places, cliffs; 2100–3300 m. S Xizang.