Tree, 5–12 m. Leaves 15–27 × 5–9.5 cm, elliptic to oblanceolate, lower surface with a thin silvery compacted indumentum. Flowers 15–25, in a dense truss, 8-lobed, cream to pale yellow, rarely with a purplish tinge, with purple nectar pouches, ventricose-campanulate, 50–70 mm; stamens 16; ovary covered with stalked glands, sometimes also with a dense pale brown tomentum. Flowering February-April. Royal Horticultural Society (1997)
Distribution Bhutan China S Tibet India NE Nepal E
Habitat 2,500-3,000 m
RHS Hardiness Rating H4
Awards FCC 1901 (F.D. Godman, South Lodge, Horsham); flowers creamy white, with a purple blotch.
Conservation status Least concern (LC)
Taxonomic note The glandular ovary will distinguish this from the remaining species in Subsect. Grandia. Royal Horticultural Society (1997)
An evergreen tree or large shrub up to 30 ft high; young shoots stout, clothed with silvery scurf. Leaves stiff and leathery, oblong to oblanceolate, tapered at both ends, 6 to 15 in. long, 3 to 6 in. wide, dark green and glabrous above, beautifully silvery or covered with dull tawny down beneath; stalk 1 to 2 in. long. Flowers sometimes twenty-five to thirty, opening during March and April in a rounded truss 5 to 7 in. wide. Calyx a mere rim; flower-stalk glandular, and it may be slightly downy, like the calyx. Corolla bell-shaped, 2 to 3 in. long and wide, ivory white, with conspicuous blotches at the base, eight-lobed. Stamens sixteen, downy at the base. Ovary downy and densely glandular; style glabrous or nearly so; stigma large, disk-like. Bot. Mag., t. 5054. (s. Grande)
Native of the Himalaya from Nepal eastward; described in 1847 from a specimen collected in Bhutan. In 1850 it was introduced from the Sikkim Himalaya by J. D. Hooker, who found it on Tonglo (west of Darjeeling) and Sinchul (S.E. of Darjeeling), both of which at that time lay within the domains of the Rajah of Sikkim. Hooker redescribed it under the name R. argenteum, which remained in use until well into this century and has not even now disappeared from garden nomenclature, though there is really no doubt that the Sikkim and Bhutan plants represent the same species. In this connection H. F. Tagg, the Edinburgh authority, wrote: ‘In its typical condition [R. grande] is characterised by the oblong-oblanceolate leaves with their silvery undersurface. Forms occur in cultivation with a rougher and somewhat tawny indumentum. It was at one time thought that these might represent R. grande as opposed to R. argenteum with its more silvery under surface. There seems little doubt that R. argenteum is a synonym of R. grande’ (The Species of Rhododendron, 2nd ed., p. 310). The synonymous name R. longifolium is founded on a narrow-leaved specimen collected by Booth in the Assam Himalaya.
One of the most magnificent of rhododendrons, this unfortunately can only be grown in the open air in the mildest counties. The finest examples are to be seen in Cornwall and western Scotland, where it has attained a height of over 30 ft.