Multi-stemmed tree, to 6 m. Leaves 11.5–17 × 4–4.5 cm, elliptic to oblanceolate, lower surface with a compacted fawn dendroid indumentum. Flowers 15–20, in a dense inflorescence, deep magenta to deep lilac, with darker nectar pouches, tubular-campanulate, 30–35 mm. Flowering April-May. Royal Horticultural Society (1997)
Distribution Bhutan W India Sikkim
Habitat 2,900–3,650 m
RHS Hardiness Rating H5
Awards AM 1951 (Mrs R.M. Stevenson, Tower Court, Ascot); flowers Imperial Purple, with darker staining. FCC 1979 (Crown Estate Commissioners, Windsor) to a clone 'Crown Equerry'; trusses containing up to 32 flowers, corolla purple-violet, with darker lip and deeper veining. AGM 1993
Conservation status Vulnerable (VU)
Taxonomic note This distinctive species is rare and threatened in the wild. Royal Horticultural Society (1997)
An evergreen shrub of sturdy habit, up to 15 ft high; young shoots clothed with a whitish felt. Leaves narrowly-oblong, 3 to 7 in. long, 1 to 21⁄2 in. wide, tapering at the base, more rounded at the apex. When the young leaves unfold they are covered all over with a snow-white floss, which falls away from the upper surface, leaving it very deep green, but which persists beneath and turns a pale brown. Flowers up to twenty, sometimes more numerous, in a compact, rounded head 3 to 4 in. across, borne on short, felted stalks. Calyx minute. Corolla tubular-campanulate, five-lobed, 13⁄8 to 2 in. long, purplish lilac or dull plum-coloured, with darker nectar-pouches at the base. Stamens ten, shorter than the corolla. Ovary felted; style glabrous, with a small stigma. Bot. Mag., t. 4730. (s. and ss. Arboreum)
R. niveum was discovered by J. D. Hooker in Sikkim in November 1849, growing around Lachen, Lachung, and Chola at 10,000 to 12,000 ft, and not uncommon there. But outside Sikkim it seems to be rare.
It is quite hardy at Kew in a sheltered position but enjoys a moister climate. The unusual colour of the flowers among rhododendrons, and the striking snowy-white covering of its young leaves, gives this species a certain distinction and makes it well worth growing, though not in the neighbourhood of pure reds, with which its flowers clash gratingly. Its flowering season is April to May.
Hooker noted that the indumentum of R. niveum is sometimes rusty-red in the wild. This form is figured in Bot. Mag., t. 6827, as var. fulvum.
R. niveum is a variable species, and some forms are much inferior to others in colour and size of flower. The Award of Merit was given on April 17, 1951, to a form with Imperial Purple flowers in trusses of up to thirty, exhibited by Mrs Stevenson, Tower Court, Ascot.
Some garden seedlings are thought to be hybrids between R. niveum and R. falconeri, e.g. ‘Colonel Rogers’, raised at Riverhill, Sevenoaks, and ‘Trevarrick’, raised in Cornwall, where hybrids of this putative parentage are fairly common. Another is ‘Mecca’, which received an Award of Merit on May 4, 1965, when exhibited by Mrs Douglas Gordon, Littleworth Cross, Surrey. In this the flowers are white with a light purple flush, in rounded trusses of up to forty-two. These plants are not further dealt with in the section on hybrids.