马关杜鹃 ma guan du juan

Shrubs, 1–2 m tall; young shoots slender, brown, densely rough-papillate-glandular. Petiole 3–4 mm, scaly; leaf blade leathery, obovate, 1.2–2.2 × 0.8–1.1 cm; base cuneate; margin revolute; apex rounded, emarginate, apiculate; abaxial surface pale green, scales 2–3 × their own diameter apart, concave; adaxial surface green; lateral veins 3–4-paired, concave above and flat below. Inflorescence terminal, 1- or 2-flowered. Pedicel brown-purple, 2–2.5 cm; calyx lobes 5, ca. 1 mm, ovate-triangular, scaly abaxially; corolla campanulate, 5-lobed, golden yellow, 0.8–1 cm, tube ca. 4 mm, outer surface scaly; lobes oblong, 0.5–0.6 cm; stamens 10, unequal, 0.7–0.8 cm; filaments villous in lower 1/2; ovary densely scaly; style 3–4 mm, glabrous; stigma capitate. Capsule not known.

Thickets in mountains; 2000–2600 m. SE Yunnan.

Rhododendron maguanense may be synonymous with R. emarginatum. According to the descriptions, the former has calyx lobes that are triangular and 1 mm, the latter has an undulate calyx. There appears to be little else to distinguish them.