Rhododendron L., Sp. Pl. 392. 1753. Gen. Pl. ed. 5.185. 1754; Boiss., Fl. Or. 3:963.
1875; C.B. Clarke, 1.c. 462; Brandis, l.c. 409; Parker, 1.c. 297.
Evergreen or deciduous shrubs or trees, often scaly, aromatic. Leaves alternate, clustered at the ends of branches, shortly petiolate, usually leathery. Flowers in terminal clusters, rarely solitary, pedicellate, often large, showy. Calyx 5-lobed, often very small. Corolla 5-lobed, less often 6-10-lobed, slightly zygomorphic, rotate, campanulate, saucer-shaped or tubular. Stamens 5-10; anthers dehiscing by apical pores. Ovary 5-10-Jocular; ovules numeĀ¬rous. Fruit capsular; dehiscence septicidal, 5-10-valvular. Seeds minute, numerous.
Rhododendron has about 800 species and is much the largest of all the genera
of Ericaceae; chiefly distributed in the mountains of Eastern Asia, the Himalayas, South West China, New Guinea, North America and certain parts of Europe.