An evergreen, erect-branched shrub described as growing up to 3 ft high in the wild, but sometimes taller in cultivation; young shoots rough with scales. Leaves elliptic, up to 3⁄4 in. long, about half as wide, slightly glaucous green and thickly set with shining yellow scales above, more sparsely scaly beneath; stalk about 1⁄8 in. long. Flowers usually solitary, with a very short scaly stalk. Calyx shorter than the corolla-tube, deeply five-lobed, the lobes blunt, oval-oblong, sparsely scaly, usually fringed with weak hairs. Corolla about 1 in. wide, purple or blue-purple, with or without scales on the outside, hairy in the throat. Stamens seven or eight, with purple filaments; anthers yellowish. Ovary densely scaly; style purple, glabrous. (s. Lapponicum)
Native of W. Szechwan; discovered by Wilson in 1908 at altitudes of 10,000 ft and upwards. It is a very hardy species, allied to R. impeditum, but taller and not flowering until May. Forms with the corolla not scaly outside would in fact run down to R. impeditum in the key in Species of Rhododendron, which is badly out-of-date. R. verruculosum received an Award of Merit when shown by Col. S. R. Clarke, Borde Hill, Sussex, on May 24, 1932.