Shrub or small tree, 1–3.8 m; bark rough; young shoots glabrous. Leaves 6.5–12.5 × 4.2–9 cm, broadly elliptic to orbicular, base rounded; upper surface glabrous, lower surface more or less glaucous, with a mamillate epidermis, glabrous or with a few scattered hairs on the midrib towards the base. Flowers 6–11, in a lax truss; calyx (2–)7–15 mm, cupular; corolla white or cream, to clear pink, with darker nectar pouches, campanulate to funnel-campanulate, (40–)50–60 mm; ovary glabrous or rarely with a few glands, style glabrous. Flowering February-April. Royal Horticultural Society (1997)
Distribution China W Yunnan
Habitat 3,000–4,000 m
RHS Hardiness Rating H5
Awards AM 1933 (Lady Loder, Leonardslee, Sussex); flowers white, flushed rose.
Conservation status Vulnerable (VU)
Taxonomic note This species has a very local distribution. It apparently hybridizes in the wild with R. lacteum. Royal Horticultural Society (1997)
An evergreen shrub 5 to 12 ft high, with glaucous green young shoots. Leaves oval to roundish, the base sometimes heart-shaped, 21⁄2 to 4 in. long, 13⁄4 to 3 in. wide; blue-green, ultimately dark green above, glaucous beneath, glabrous or nearly so; stalk stout, 1⁄2 to 11⁄8 in. long. Flowers in trusses of as many as ten, fragrant. Calyx cup-shaped, up to 1⁄2 in. long, with five broad lobes, glabrous, glaucous. Corolla between funnel-shaped and bell-shaped, about 2 in. long, varying from white or creamy white tinged with rose to rich rose, five-lobed, the lobes 1 in. wide and notched in the middle; stamens ten, their stalks smooth, anthers brown; ovary and style glabrous, eglandular (but ovary glandular in var. eriphyllum Tagg). Bot. Mag., n.s., t. 155. (s. and ss. Thomsonii)
Native of W. Yunnan, China, at 10,000 to 12,000 ft altitude; originally discovered by the Abbé Delavay, who only saw the plant in its seed-bearing state. It remained a rather mysterious plant until Forrest, in 1906, collected it in flower on the Tali range, to which it seems to be confined. It was then seen, as Franchet had duly noted, to be closely related to the Himalayan R. thomsonii, but to differ in the colour of the flowers (those of R. thomsonii are blood-red) and in their being fragrant, also in the larger, more oval, and more conspicuously veined leaves. Both have a large, cup-shaped, characteristic calyx and the bluish or bluish- purple seed-vessel to which the specific name refers. The species is in cultivation in southern and western gardens, where it flowers in March and April.