曲枝杜鹃 qu zhi du juan

Replaced synonym: Rhododendron torquatum L. C. Hu, Acta Phytotax. Sin. 30: 549. 1992, not R. torquatum I. B. Balfour & Farrer, Notes Roy. Bot. Gard. Edinburgh 13: 303. 1922.

Shrubs, caespitose, ca. 3.5 m tall; shoots twisted, sparsely whitish pilose. Petiole flattened, short and broad, 6–8 × ca. 5 mm, glabrescent; leaf blade leathery, lanceolate to obovate-lanceolate, 11–14 × 4–4.5 cm; base cuneate; margin slightly revolute; apex shortly acuminate, mucronate; abaxial surface indumentum white, 1-layered, agglutinated; adaxial surface glabrous. Inflorescence racemose-umbellate, ca. 10-flowered; rachis short, yellow-floccose. Pedicel 2–2.5 cm, sparsely white-floccose; calyx lobes 5, 1–1.5 mm, triangular, similarly floccose; corolla funnel-campanulate, white to pale pink, with purple spots inside and sparsely puberulent at base, 2.5–3 × ca. 2.5 cm; lobes 5; stamens 10, unequal, shorter than corolla, filaments puberulent at base; ovary narrowly cylindric, ca. 6 × 3 mm, glabrous; style ca. 2 cm, glabrous, stigma capitate. Fl. Jun.

Abies forests, Picea forests, mountain slopes; ca. 3600 m. S Gansu.

The type of Rhododendron torquatum L. C. Hu closely resembles R. watsonii, sharing with that species a flattened, winged petiole, a white, compacted leaf indumentum, and a glabrous ovary. The latter species, which belongs to R. subsect. Grandia, differs in having a 6- or 7-lobed corolla. If R. torquescens indeed has a 5-lobed corolla, as described in the protologue of R. torquatum, then it is probably correctly placed in R. subsect. Taliensia.