An evergreen shrub 2 ft or less high, of compact habit; young branchlets hairy and covered with brown scurf; leaf-bud scales deciduous. Leaves oval or ovate, 1 to 11⁄2 in. long, 1⁄2 to 3⁄4 in. wide, dark, rather glossy green above, covered with brown scales beneath; stalk 1⁄4 in. long. Flowers white, pink, or sulphur-coloured, 1⁄2 to 3⁄4 in. across, produced in a small terminal cluster, 1 to 11⁄2 in. wide. Corolla thin, almost transparent, tube hairy inside expanding at the mouth into five wavy lobes; calyx-lobes oblong, pale green, 1⁄8 in. long, fringed at the margin; stamens five to eight, very short, and included within the tube; flower-stalk scaly, 1⁄/6 in. or less in length; style short and thick. Flowers in April. Bot. Mag., t. 3947. (s. Anthopogon)
Native of the high Himalaya from Kashmir eastwards, up to 16,000 ft altitude, where it covers large areas; introduced in 1820. The whole plant has a strong, aromatic, slightly acrid odour, especially when crushed. It is an interesting little plant, and one of the hardiest of Himalayan species, but not in any way showy.
The Award of Merit was given on April 29, 1969 to the clone 'Betty Graham', with deep pink flowers, raised from Ludlow and Sherriff 1091 and shown by E. H. M. and P. A. Cox.
R. hypenanthum Balf. f. – This rhododendron is very closely related to R. anthopogon and was not distinguished from it until 1916. In the true R. anthopogon the scales that surround the base of the winter-buds fall away as soon as, or soon after, the leaves open; but in R. hypenanthum these scales – triangular, overlapping, and ciliate – remain clasping the twigs for several years. So far as is known, the flowers in R. hypenanthum are always yellow. It is a native of the Himalaya, but has not yet been found east of Nepal.