333. Rhododendron coryanum Tagg & Forrest, Notes Roy. Bot. Gard. Edinburgh. 15: 99. 1926.
光蕊杜鹃 guang rui du juan
Shrubs, ca. 3–6 m tall; branchlets brownish, ca. 4 mm in diam., grayish pubescent. Petiole cylindric, grooved adaxially, 15–20 mm, thinly tomentose, with a few short glandular hairs; leaf blade leathery, long-elliptic to oblong-lanceolate, 7–14 × 2–3 cm; base tapering, cuneate; apex acute to acuminate; abaxial surface indumentum thin, silvery grayish or whitish, soft and suedelike, also with sparsely scattered very small glands; adaxial surface green, glabrous; midrib prominent abaxially, grooved adaxially, lateral veins 15–20-paired, slightly impressed adaxially. Inflorescence 15–20-flowered; rachis 20–30 mm, puberulent. Pedicel 3–4 cm, sparsely tomentose and glandular; calyx lobes 5, ca. 2 mm, ovate or triangular, sparsely tomentose; corolla funnel-campanulate, creamy-white or whitish with brownish crimson spots, 2.5–3 cm, puberulent inside; lobes 5, orbicular, ca. 1.5 cm; stamens 10, unequal, 2–2.5 cm, filaments puberulent at lower part; ovary conoid, ca. 5 mm, glabrous; style 2–2.5 cm, slender. Capsule cylindric, slightly curved, 15–25 × 4–6 mm, glabrous. Fl. Jun, fr. Aug–Oct.
Abies forests, Rhododendron thickets; 2600–3700 m. SE Xizang, NW Yunnan.