Description from Flora of China
Rhododendron brettii Hemsley & E. H. Wilson; R. longesquamatum var. glabristylum Y. Y. Geng & Z. L. Zhao.
Shrubs or small trees, 1–6 m tall; bark grayish; young shoots stout, with persistent perulae and densely shaggy, hairs coarse, branched. Petiole stout, 10–20 mm, tawny shaggy; leaf blade leathery, oblong-oblanceolate to narrowly obovate, 5.5–15.5 × 2–4.5 cm; base rounded to subcordate; margin revolute; apex acute; abaxial surface pale green, midrib tawny shaggy, otherwise glabrous when mature; adaxial surface dark green, glandular-hairy and rufous-tomentose, midrib prominent abaxially, grooved adaxially; lateral veins 12–14-paired. Inflorescence racemose-umbellate, 6–12-flowered; rachis 3–6 mm, rufous-tomentose. Pedicel 2–3.5 cm, glandular-hairy; calyx cupular; lobes 5, 8–13 mm, unequal, lingulate, glandular-hairy, 6–12 mm; corolla open-campanulate, rose-pink, with deep crimson basal blotches, ca. 4 cm, lobes 5, suborbicular, ca. 1.3 × 2.2 cm, emarginate; stamens 10, unequal, 2–2.5 cm, filaments pubescent at base; ovary ovate, 4–5 mm, glandular-hairy; lower half of style glandular-hairy. Capsule cylindric, curved, ca. 20 × 6 mm. Fl. Jun, fr. Sep.
Plants with the leaf blade midrib generally glabresent, calyx lobes tomentose, eglandular, and style glabrous have been described as var. glabristylum Y. Y. Geng & Z. L. Zhao (Acta Phytotax. Sin. 41: 197. 2003).
Usually in Abies forests; 2300–3400 m. W Sichuan.