322. Rhododendron ririei Hemsley & E. H. Wilson, Bull. Misc. Inform. Kew. 1910: 111. 1910.
大钟杜鹃 da zhong du juan
Shrubs or small trees, 3–8 m tall; bark pale gray, exfoliating into thin and small irregular flakes; young shoots stout, pale green, glabrous. Petiole stout, 10–20 mm, glabrous; leaf blade oblong-elliptic to obovate-elliptic, 7.5–13 × 2.5–4 cm; base broadly cuneate or rounded; apex cuspidate and mucronate; abaxial surface indumentum silvery white, thin; adaxial surface dark green, glabrous, midrib prominent abaxially, impressed adaxially; lateral veins 13–14-paired, prominent abaxially. Inflorescence racemose-umbellate, 5–10-flowered; rachis 5–8 mm, whitish pilose. Pedicel 1–1.5 cm, with a white tomentum; calyx lobes 5, small, unequally triangular, sparsely pubescent; corolla campanulate, broad at base, purple-red, 4–6 cm, with 5 black-purple nectar pouches at the base of tube, lobes 5, orbicular, emarginate; stamens 10, subincluded in the corolla, 2.5–5.5 cm, filaments glabrous; ovary cylindric or conoid, 5–8 mm, 10-locular, densely gray felted-tomentose; style 3–3.5 cm, glabrous. Capsule oblong-cylindric, 2–3 × 9–12 mm, grayish tomentose when young, glabrescent. Fl. Mar–May, fr. Jul–Aug.
Forests; 1700–1800 m. SW Sichuan.
Rhododendron ririei subsp. leiboense M. Y. Fang (Acta Phytotax. Sin. 30: 556. 1992), described from Sichuan (Leibo), is said to differ in having the leaf blade more narrowly oblanceolate to elliptic-lanceolate, less leathery, with a silvery indumentum abaxially and a cuneate base, pedicels more slender, and corolla with a narrower base. This taxon was not included in FRPS.