An evergreen shrub probably 4 to 5 ft high, of rather stiff habit; young shoots reddish, scaly, becoming bright brown and smooth the second season. Leaves oblong to narrowly oval, usually tapered at the apex (sometimes rounded) to a mucro, tapered at the base, 11⁄2 to 21⁄2 in. long, 1⁄2 to 1 in. wide, dark glossy green above, slightly scaly and very glaucous beneath; stalk 1⁄8 to 1⁄4 in. long. Flowers from three or four to as many as eight or ten in a cluster, each on a slender scaly stalk 3⁄4 to 11⁄2 in. long. Calyx green, scaly outside, very large for the size of the flower, 5⁄8 to 3⁄4 in. wide with five leaf-like rounded lobes spreading out away from the corolla. Corolla clear pale yellow or tinged with green, bell-shaped with five broadly ovate, pointed, recurved lobes; 5⁄8 in. long, 3⁄4 to 1 in. wide. Stamens ten, shorter than the corolla, clothed with pale hairs to the middle and upwards; ovary scaly; style about as long as the stamens, quite smooth, swelling to a broad stigma at the top. Bot. Mag., t. 8750. (s. and ss. Glauco-phyllum)
R. brachyanthum was discovered by the Abbé Delavay in the mountains above Tali about 1884; it was found again by Forrest in 1906 in the same range at 10,000 to 11,000 ft and was introduced by him. It seems to be more local in the wild, and rarer in cultivation than the var. hypolepidotum. In its best form this is a charming and distinct species with flowers shaped like those of a campanula and of a pleasing yellow, with a large foliaceous calyx. But in other forms the green-tinted flowers are dull. It seems to be quite hardy and flowers about midsummer. Although so different in colour, the flowers in shape of corolla and size of calyx strongly resemble those of R. glaucophyllum. The seed-vessel in both is hidden by the persistent calyx, and the leaves of both have a strong odour.
Award of Merit May 23,1966, when shown by Collingwood Ingram, Benenden, Kent (clone 'Jaune').
var. hypolepidotum Franch. R. hypolepidotum (Franch,) Balf. f. & Forr.; R. charitostreptum Balf. f. & Ward – This differs from the type only in having the underside of the leaves much more densely scaly and glaucous green rather than whitish. Bot. Mag., t. 9259. It has a fairly wide distribution in N. Burma and bordering parts of Yunnan. Forrest, who introduced it, sent seeds from the Salween-upper Irrawaddy and Mekong-Salween divides; Kingdon Ward from the Imaw Bum, where it grows near the summit with R. aperantum and also from the Seinghku valley (both in upper Burma); and Rock from Tsechung (Mekong watershed). Award of Merit June 26, 1951, when shown by the Crown Estate Commissioners, Windsor Great Park (clone 'Blue Light').
R. shweliense Balf. f. & Forr. – Very near to R. brachyanthum var. hypolepidotum, differing in the corolla being pink, tinged with yellow and densely scaly outside. Introduced by Forrest from the Shweli-Salween divide, Yunnan, in 1924. It is uncommon in cultivation.
From the Supplement (Vol. V)
subsp. hypolepidotum (Franch.) Cullen R. brachyanthum var. hypolepidotum Franch. – This is more widely distributed than the typical state (Rev. 1, p. 144).
R. shweliense – This species is recognised, but Dr Cullen remarks that most plants cultivated under the name are R. glaucophyllum or hybrids of it (Rev. 1, p. 143).