An evergreen shrub of erect habit up to 3 ft high; young shoots very scurfy. Leaves elliptic-lanceolate, tapered about equally to both ends, 1⁄4 to 1⁄2 in. long, 1⁄10 to 3⁄16 in. wide, dull dark green above, pale brown below, very scaly on both sides; stalk 1⁄16 in. long. Flowers solitary, in pairs or threes, opening in April or May. Calyx about 1⁄16 in. long, scaly. Corolla widely funnel-shaped, 1⁄2 in. wide, five-lobed, rosy purple, the lobes more or less scaly up the centre outside. Stamens normally ten, sometimes less, downy towards the base. Ovary scaly; style glabrous, overtopping the stamens. (s. Lapponicum)
Native of S.W. Szechwan and bordering parts of Yunnan; discovered by Forrest and introduced by him from the Chungtien plateau in 1914. It belongs to a group of the Lapponicum series in which the undersides of the leaves have a close covering of brownish or greyish scales dotted with darker, larger, stalked scales. It is a very hardy species, suitable for the rock garden, but not among the best of the series.
A rhododendron scarcely differing from R. telmateium was found by Ludlow and Sherriff in a dry zone of the Tibetan Himalaya.
R. diacritum Balf. f. & W. W. Sm. R. pycnocladum Balf. f. & W. W. Sm. – Very near to R. telmateium, but with the leaves oblong or oblong-elliptic. The type is from the Chungtien plateau.
R. drumonium Balf. f. & Ward – Leaves similar to those of R. diacritum. Style slightly shorter than the stamens. Otherwise very like R. telmateium. The type, collected by Kingdon Ward below the Chungtien plateau, was a dwarf carpet-forming shrub, but Forrest's 13768 from the same area came from plants 2 to 21⁄2 ft high.
From the Supplement (Vol. V)
R. diacritum and R. drumonium, mentioned under this species, are included in it by the Philipsons; R. idoneum Balf.f. & W.W. Sm. is another synonym (Rev. Lapp., pp. 47-50). As now understood, the species is of wider range than stated, occurring in central Yunnan as well as in the northern and north-western parts of the province and bordering Szechwan. The leaves of R. telmateium are never much over 1⁄2 in. long and often only half that length, varying in shape from elliptic to almost orbicular. The species in variable in the length of the style, which may be longer or shorter than the stamens, or of about the same length. The scales of the undersides of the leaves are closely set, pale gold or light brown, usually with a scattering of darker scales. In common with many other members of the subsection it is variable in habit but usually erect in cultivated plants, to 2 or 3 ft. A well-marked character is that the leaves are always distinctly mucronate.
It was mentioned on page 783 that a rhododendron scarcely differing from R. telmateium was found by Ludlow and Sherriff. This was R. bulu Hutch., described from a specimen collected by Kingdon Ward in south-east Tibet. It is indeed very closely allied to R. telmateium, differing mainly in its longer leaves. It is not in cultivation.