凸纹杜鹃 tu wen du juan

Small trees, 6–8 m; young branches gray, glabrous. Petiole 8–15 mm, grooved adaxially, glabrous; leaf blade elliptic to narrowly elliptic, 7–10.5 × 1.8–2.5 cm; base cuneate; margin slightly revolute; apex long-acuminate; both surfaces glabrous; lateral veins 12–16-paired, prominent. Inflorescence subapical, umbellate, 4- or 5-flowered, rachis ca. 5 mm. Pedicel 2–2.5 cm, glabrous; calyx rim with tufts of long weak hairs; lobes narrowly triangular to narrowly lingulate, 5–20 × ca. 1 mm, sometimes minutely ciliate; corolla narrowly funnelform, pale rose, ca. 4.5 cm, tube ca. 10 mm, outer surface glabrous; lobes 3–3.5 × ca. 1 cm; stamens 10, shortly exserted, 3–3.5 cm, filaments puberulent in lower half; ovary narrowly cylindric, truncate at insertion of style, densely yellowish tomentose; style 3–3.5 cm, glabrous. Capsule not known. Fl. May.

Evergreen broad-leaved forests; 1900–2000 m. SE Yunnan.

This species resembles Rhododendron cavaleriei, but differs in the prominent lateral veins of the leaf blade, the longer calyx lobes, and the ovary, which is truncate at the apex.