Shrub, to 3 m; young shoots densely covered with adpressed flattened grey to reddish brown hairs. Leaves of one kind, persistent, 1–3(–5.5) × 0.5–1(–2.5) cm, oblong-lanceolate to elliptic, apex acute, with a glandular mucro, upper surface with pale grey adpressed hairs, lower surface covered with flattened adpressed red-brown hairs, especially on the midrib; petioles densely covered with adpressed flattened red-brown hairs. Pedicels densely bristly. Flowers 2–4 per inflorescence; calyx minute; corolla pink, with rose flecks, funnel-shaped, 10–15(–25) mm; stamens 7–10; ovary covered with pale grey soft hairs, style more or less glabrous. Flowering May. Royal Horticultural Society (1997)
Habitat 2,400–3,000 m
RHS Hardiness Rating H5
Conservation status Least concern (LC)
An evergreen azalea up to 9 ft high in the wild; young shoots covered densely with flattened, appressed, grey to red-brown hairs. Leaves oblong-lanceolate to oval-lanceolate, 1⁄2 to 13⁄4 in. long, 1⁄2 to 3⁄4 in. wide, slightly hairy above, thickly furnished beneath with forward-pointing bristly hairs, especially on the midrib. Flowers in clusters of three or four. Calyx and flower-stalks bristly. Corolla funnel-shaped, with five spreading lobes, pink spotted with dark rose, 3⁄4 to 1 in. wide. Stamens seven to ten, shorter than the corolla, downy near the base as is also the longer style. (s. Azalea ss. Obtusum)
Native of Formosa, up to 10,000 ft altitude. Wilson, who visited its native habitat in 1918, found many plants flowering in October. During the same journey he introduced the species to cultivation by means of seeds. It is not likely to be hardy except in such climates as that of Cornwall. It differs from R. indicum in the more numerous stamens and in the downy style; the latter character distinguishes it also from R. tosaense and R. simsii. W. R. Price, who visited Formosa in 1912, also found it blooming in October. It is uncertain whether this species is still in cultivation.
The only significant difference between these two varieties, both of which are rare in cultivation and frost-sensitive, is in the form of the stamens.
Stamens not appendiculate.