Shrub or tree, 1.3–10 m. Leaves 10–19(–30) × 4–7.5(–10) cm, oblong, base rounded, glabrous. Flowers 4–5, in a lax truss; calyx 7–20 mm long, lobes rounded; corolla 5-lobed, pale pink at first, soon fading white, open-campanulate, nectar pouches lacking, 55–80 mm; stamens 12–18; ovary and entire style glandular. Flowering April-May.
A distinctive species that requires a mild climate in Britain and is thus rare in cultivation. It has been used widely to produce many worthy garden hybrids. Royal Horticultural Society (1997)
Distribution Bhutan India Bengal, Sikkim, Arunachal Pradesh Nepal E
Habitat 2,100–2,850 m
RHS Hardiness Rating H4
Awards FCC 1866 (J. Standish, Ascot) as R. griffithii.
Conservation status Least concern (LC)
An evergreen shrub, or occasionally a small tree, with erect branches and peeling bark. It is quite devoid of down or hairs in all its parts. Leaves narrowly oblong, 6 to 9 (sometimes 12) in. long, about one-third as much wide; rather pale green above, slightly glaucous beneath; stalk 1 to 11⁄2 in. long. Flowers white with a pink tinge, slightly fragrant, 5 or 6 in. diameter, produced loosely in a cluster of about six. Calyx 3⁄4 to 1 in. across, buckler-like, scarcely lobed. Corolla widely bell-shaped, with five large, rounded lobes notched in the middle; stamens up to sixteen, much shorter than the corolla; style 11⁄2 in. long, with a large knob-like stigma; flower-stalk 1 to 13⁄4 in. long. Bot. Mag., t. 5065. (s. Fortunei ss. Griffithianum)
Native of the Himalaya from E. Nepal eastward, and of the Mishmi Hills, Assam, apparently everywhere uncommon; described from a specimen collected by Griffith in Bhutan; introduced in 1850 by J. D. Hooker from Sikkim, where he found it growing at 7,000 to 9,000 ft in the inner ranges. In some respects this is the finest of all rhododendrons, especially in regard to the size and width of the individual flower, which resembles some fine lily and is occasionally 7 in. across. But it is variable in the size both of its flowers and of its leaves.
R. griffithianum is not hardy near London, but in the mildest parts it has a height and width of 20 ft or even more. There is a fine specimen growing under glass at Edinburgh, raised from seeds collected by Roland Cooper in Bhutan in 1914, and now 20 ft high.
Many of the finest first-generation hybrids have R. griffithianum as one parent, and details of the best-known of these will be found in the section on hybrids. See also p. 820 for a note on the hardy hybrids deriving from R. griffithianum, of which ‘Pink Pearl’ is the type.