Rhododendron thayerianum Rehder & E. H. Wilson

Shrubs, 3–4 m tall; branches stout, thick; bud scales persisting among the leaves for several years, membranous or thinly leathery, ovate or lanceolate, 2–3.5 cm. Petiole cylindric, stout, grooved adaxially, 10–15 mm, sparsely glandular, glabrescent; leaf blade leathery, narrowly oblanceolate, 9–17 × 1.5–2.5 cm; base cuneate; margin revolute; apex acuminate; abaxial surface, except midrib, sparsely glandular and with thinly silvery to fawn indumentum; adaxial surface glabrous; midrib prominent abaxially, deeply grooved adaxially; lateral veins 10–12-paired, impressed. Inflorescence a racemose corymb, 10–20-flowered; rachis 30–40 mm, shortly glandular-hairy. Pedicel slender, 3–5 cm, densely glandular; calyx lobes 5, unequal, ovate, densely glandular, 2–4 mm; corolla funnel-campanulate, white, sometimes deeply flushed pink on the outside along the petal ridges, or pink, without spots, 2–3 cm, lobes 5, orbicular, ca. 1.3 × 1–1.5 cm; stamens 10, unequal, 1.5–2 cm, filaments with base widened and floccose; ovary oblong, ca. 5 mm, 6–8-locular, with translucent whitish glands; style 2–2.5 mm, glandular to tip. Capsule oblong-cylindric, ca. 25 × 6 mm. Fl. May–Jun, fr. Aug–Oct.

W Sichuan.

Woodlands; 2600–3000 m.

Rhododendron thayerianum (反边杜鹃) is a rhododendron species native to western Sichuan in China, where it grows at altitudes of 2,600–3,000 m (8,500–9,800 ft). It is an evergreen shrub that grows to 3–4 m (9.8–13.1 ft) in height, with leathery leaves that are narrowly oblanceolate, and 9–17 × 1.5–2.5 cm in size. The flowers are white, sometimes deeply flushed pink on the outside along the petal ridges, or pink. It flowers quite late in the season, in June and July.