Rhododendron davidsonianum Rehder & Wilson

Shrubs, 1–3 m tall; young shoots sparsely or rarely densely scaly, otherwise glabrous or pubescent. Petiole 3–5 mm, scaly, pubescent; leaf blade lanceolate or oblong, 2.5–6 × 1–2 cm; base narrower or obtuse, V-shaped; apex acute, apiculate; abaxial surface scales 1–4 × their own diameter apart or contiguous, unequal, yellowish brown; adaxial surface deep or fresh green, sparsely scaly, glabrous or pubescent along midrib. Inflorescence terminal or subterminal, shortly racemose, 3–6-flowered; rachis 2–4 mm. Pedicel 1–1.5 cm, sparsely scaly, pubescent; calyx rimlike or 5-lobed, 0.5–1 mm, scaly; corolla broadly funnelform-campanulate, pale purplish white or rosy red, with red or yellow spots inside, 2.5–3 cm, outer surface scaly or not; stamens unequal, long ones longer than corolla; filaments pubescent below; ovary 5-locular, densely scaly; style longer than corolla, glabrous. Capsule cylindric, 10–13 mm. Fl. Apr–May, fr. Sep–Oct.

Sichuan.

Coniferous forests, open areas in forests, thickets; 1500–2800(–3600) m.

Rhododendron davidsonianum, the concave-leaf rhododendron, is a species of flowering plant in the heath family Ericaceae that is native to the forests of Sichuan, China, where it lives at altitudes of 1,500–2,800 m (4,900–9,200 ft). Growing to 4 m (13 ft) tall and 2.5 m (8.2 ft) broad, it is an upright evergreen shrub. The glossy leaves are lanceolate and up to 6 cm (2.4 in) long. In Spring trusses of bell-shaped, pale pink or purple flowers are produced.

In cultivation in the UK, Rhododendron davidsonianum has gained the Royal Horticultural Society’s Award of Garden Merit. Like most rhododendrons it prefers an acid soil. It is hardy down to −15 °C (5 °F).