178. Rhododendron rushforthii Argent & D. F. Chamberlain, New Plantsman. 3(4): 195. 1996.
滇越杜鹃 dian yue du juan
Small shrubs, perhaps epiphytic, to 1.5 m tall; older shoots ash-gray. Petiole 8–15 mm; leaf blade thick, glaucous, especially when young, elliptic, 1.8–11 × 1.7–4.2 cm; base cuneate, narrowly decurrent; margin cartilaginous; apex broadly acute, apiculate; abaxial surface scales scattered, brown; adaxial surface scaly, at first silvery, turning brown and quickly lost, midrib and lateral veins impressed. Inflorescence terminal, umbellate, 3–8-flowered. Pedicel 1–1.4 cm; calyx lobes 3–4 mm, triangular, unequal; corolla shortly campanulate, yellow, 1–1.5 cm, tube 4–7 mm, outer surface finely scaly, mouth hairy; stamens 10, 0.8–0.9 cm, filaments hairy in lower half though glabrous at base; ovary ca. 4 mm; style arched, ca. 5 mm; stigma capitate. Capsule not known. Fl. (in cultivation) Jun.
Probably epiphytic, also mossy banks. S China (see note below) [N Vietnam].
This species is closely allied to Rhododendron datiandingense, and may be conspecific, although the flowers are significantly larger. The glaucous leaves are a significant feature of R. rushforthii. It was originally described from Lao Cai Province, N Vietnam, close to the border with S Yunnan at Pingbian. It is known from cultivated material said to have come from S China.