Rhododendron augustinii Hemsl.

Shrubs, 1–5 m tall; young shoots scaly, densely villous and pubescent or glabrous. Petiole 3–5(–10) mm, densely hispid and pubescent or glabrous; leaf blade elliptic, oblong or oblong-lanceolate, 3–7 × 1–3.5 cm; base cuneate to rounded; apex acuminate to acute, apiculate; abaxial surface scales (1–)1.5–5 × their own diameter apart, unequal, densely yellowish white-pubescent along lower half of midrib, mature leaves less hairy; adaxial surface scales absent or sparse to dense, densely or sparsely pubescent, with filiform-acicular hairs along midrib. Inflorescence terminal, umbellate, 2–6-flowered; rachis ca. 5 mm, glabrous. Pedicel 0.8–1.5 cm, sparsely scaly, pubescent or glabrous; calyx lobes 0.5–2 mm, rounded or triangular, densely scaly, densely pubescent or glabrous; corolla broadly funnelform-campanulate, 5-lobed to middle, blue to lavender, sometimes pale pinkish purple or white, 3–3.5 cm, outer surface glandular scaly or not, glabrous or pubescent at base; lobes oblong; stamens unequal, 2.5–3.5 cm, longer than corolla; filaments densely villous below; ovary 5-locular, densely scaly; style longer than corolla, glabrous or pubescent at base. Capsule cylindric; base oblique, 10–20 mm, densely scaly. Fl. Apr–May, fr. Jul–Aug.

Gansu, Hubei, Shaanxi, Sichuan, Yunnan.

Forests, thickets, rocks on slopes; 1000–3400(–4200) m.

Rhododendron augustinii, called the blue rhododendron or Augustine's rhododendron, is a species of flowering plant in the genus Rhododendron native to central China and Tibet. Its Electra Group has gained the Royal Horticultural Society's Award of Garden Merit.