An evergreen, stoudy branched shrub up to 6 ft high, glabrous in all its parts; young shoots glaucous. Leaves oval or inclined to obovate, broadly tapered to rounded at the base, rounded and with a short mucro at the apex; 3 to 5 in. long, 2 to 3 in. wide; dark dull green above, paler green beneath; stalk stout, 1⁄2 to 11⁄4 in. long. Flowers in a terminal truss of five to ten, opening in March and April, on glandular, reddish stalks up to 1 in. long. Corolla deep crimson, tubular-campanulate, 21⁄2 in. long and wide, five-lobed, the lobes shallow, rounded and notched; stamens ten, with white stalks, shorter than the corolla. Ovary and style eglandular. Bot. Mag., t. 9636. (s. and ss. Thomsonii)
R. meddianum appears to be a local species, known only from the mountains between the eastern Irrawaddy and the Salween, near the borders between Yunnan and Burma. It was discovered by Forrest in 1917 on the Shweli-Salween divide at 10,000 to 11,000 ft. It is an eastern representative of the Himalayan R. thomsonii, with a similar bark, but with larger, less rounded leaves and usually longer corollas. According to Forrest's field notes the colour of the flowers varies from deep crimson to almost black crimson, or even blue-black with a plumlike bloom on the outside. Many of the cultivated plants belong to the var. atrokermesinum Tagg, which really differs from the typical state only in having a densely glandular ovary, though the varietal epithet refers to the colour of the flowers in the wild plants, which according to Forrest is 'deep purple crimson' or 'deep wine crimson'. Curiously enough, the usual flower-colour in cultivated plants, both of the typical state and of the variety, is a splendid crimson-scarlet.
R. meddianum is hardy in woodland south of London and makes a fine display in March or April, weather permitting. The var. atrokermesinum received an Award of Merit when shown by Olaf Hambro, Logan, Wigtownshire, on April 13, 1954. The clone 'Machrie', which received the same award on April 13, 1965, is now considered to be a hybrid of R. meddianum, not the true species.