An evergreen shrub of stiff, wide-spreading habit, rarely more than 3 to 4 ft high out-of-doors near London; young branchlets covered with bristly hairs. Leaves oval or obovate, tapering sometimes equally to both ends, sometimes more gradually towards the base, 2 to 4 in. long, 3⁄4 to 11⁄2 in. wide, bristly on the upper surface and on the margins, scaly beneath; stalk bristly, 1⁄4 to 1⁄3 in. long. Flowers beautiful rosy red in bud, pale pink on opening, becoming almost white with age, 21⁄2 in. across, produced three to five in a cluster during March and April. Calyx-lobes rounded ovate, bristly on the margins. Corolla widely bell-shaped, with broad notched lobes. Stamens ten, hairy at the base. Ovary scaly; style glabrous. Bot. Mag., tt. 4648, 7686.
(s. Maddenii ss. Ciliicalyx)
Native of the Himalaya from E. Nepal eastward; discovered by J. D. Hooker in Sikkim and introduced by him in 1850. Hooker found it in valleys of the interior at 9,000 to 10,000 ft, 'growing in clumps 2 ft high, generally in moist rocky places'. It flowered at Kew in 1852, and was figured in the Botanical Magazine the same year with the varietal epithet roseo-album. The explanation for this quite superfluous addition is that Hooker never saw the species in full flower and sent home to his father at Kew a colour sketch made apparently from a truss in which the flowers had aged to a deep purplish pink, as shown in the plate in Rhododendrons of the Sikkim Himalaya, which was drawn and coloured from his sketch and herbarium specimens.
R. ciliatum is a perfectly hardy species and is best suited in a lightly shaded position protected from the east and north. It frequently gives a very charming display in April if the weather be kind, but a few degrees of frost will ruin it.
Crossed with other hardy species, R. ciliatum has given rise to several attractive hybrids, of which the best known are the Praecox and Cilpinense grexes. It is also the parent of such half-hardy hybrids as 'Princess Alice' and 'Countess of Haddington'.