Shrub, 1.2–3.7 m; bark rough; young shoots glabrescent. Leaves 4.5–7 × 1.8–4 cm, narrowly obovate to elliptic, base rounded, upper and lower surfaces glabrous, lower epidermis shortly papillate, with some red sessile glands; petioles with a sparse covering of rufous dendroid hairs that extend up the midrib on the upper surface of the leaves. Flowers 4–7, in a lax truss; calyx c. 1.5 mm; corolla crimson to scarlet, or white with a crimson border, nectar pouches darker, campanulate, 35–45 mm; ovary and style stalked-glandular. Flowering May-June. Royal Horticultural Society (1997)
Distribution Myanmar NE China SE Tibet
Habitat 3,200–3,800 m
RHS Hardiness Rating H5
Conservation status Least concern (LC)
Taxonomic note This is a distinctive species unlikely to be confused with any other. Royal Horticultural Society (1997)
An evergreen shrub up to 10 ft high, sometimes a small tree twice that height in forests; branchlets glandular or eglandular. Leaves leathery, oblong-elliptic, elliptic, or oblanceolate, 2 to 4 in. long, 7⁄8 to 13⁄4 in. wide, obtuse or rounded at the apex, glabrous on both sides, midrib and main veins impressed above. Flowers borne in May or early June in trusses of five to seven on glandular stalks up to 3⁄4 in. long. Calyx very small, glandular on the rim. Corolla five-lobed, campanulate, 11⁄2 to 17⁄8 in. long, scarlet, crimson, or creamy white with a cherry-red band at the mouth; nectaries dark purple or almost black. Stamens ten, with glabrous filaments. Ovary conoid, glandular; style glandular throughout. Bot. Mag., t. 9538. (s. Thomsonii ss. Cerasinum)
R. cerasinum was discovered by Kingdon Ward in 1924 on the Doshong La, a pass in Tibet at the eastern end of the Himalaya. ‘It grew in dense drenched thickets by the torrent, as a bush 8 to 10 ft high; later we found it in the forest, a bigger bush, or small tree, 15 to 20 ft high. The flowers are large, fleshy, in loose drooping trusses of five, and of an intense burning scarlet; at the base of the corolla are five circular jet-black honey-glands, each about the size of a shirt-button.’ This is the form that he nicknamed “Coals of Fire” (KW 5830).
Two years later Kingdon Ward found the same species in upper Burma overhanging a torrent that flows into the Seinghku river, one of the feeders of the Irrawaddy. In this form, which he nicknamed “Cherry Brandy”, the flowers are cherry-red throughout, or creamy white at the base with a cherry-red rim (KW 6923). As it happened, Tagg chose this form as the type of the species, whence the epithet cerasinum. The nickname is not very apt for either subform but on the collector’s recommendation it has continued to be used for the plants raised from KW 6923 to distinguish them from the Doshong La form, i.e., “Coals of Fire” (Gard. Chron., Vol. 87 (1930), p. 330).
An Award of Merit was given in 1938 to the self-coloured subform of “Cherry Brandy”, when shown from Nymans, Sussex, on June 8 (Gard. Chron., Vol. 103 (1938), p. 442 and fig. 179). The picotee form with the white, red-rimmed flowers has never received an award, though it is very charming. Unfortunately, R. cerasinum is rather shy-flowering in many gardens, though it grows well and is perfectly hardy.