Azalea farrerae (Sweet) K. Koch; A. squamata Lindley; Rhododendron cinereoserratum P. C. Tam; R. farrerae var. leucotrichum Franchet.

Shrubs, deciduous, 1.5–3 m tall; branches short and firm, ferruginous-villous, glabrescent. Petioles ca. 2 mm, densely ferruginous-pubescent; leaf blade subleathery, ovate, 2–3(–5.5) × 1–2 cm; base rounded; margin ciliate; apex obtuse, mucronate; midrib glabrous, or coarse ferruginous-strigose on both surfaces at base. Inflorescence terminal, 1- or 2-flowered, flowers opening before leaves. Pedicel ca. 0.6 cm, to 1 cm and curved in fruit, densely red-brown-pubescent or villous; calyx inconspicuous, lobes densely ferruginous villose; corolla rotate-funnelform, lilac-purple, with purple-red flecks, 2–3 × 3.8–5 cm; tube short, narrowly cylindric; lobes spreading, margin undulate, glabrous; stamens 8–10, unequal, shorter than corolla, filaments glandular-hairy below; ovary ovoid, densely red-brown-villous; style curved, glabrous. Capsule cylindric, ca. 10 mm, densely ferruginous-pubescent. Fl. May–Jun, fr. Jul–Aug.

Rhododendron cinereoserratum is better treated as a synonym of R. farrerae, not of R. mariesii as was given in FRPS (57(2): 372. 1994).

Rhododendron farrerae has also been reconfirmed in Taiwan (see Lu Sheng-You et al. 2010. Taiwania 55(2): 180-185).

Dense mountain forests; 800–2100 m. Chongqing, Fujian, Guangdong, Guangxi, Hunan, Jiangxi.