Rehder
Description
Rhododendron glaucophyllum is an Eastern Himalayan shrub distributed across Sikkim and adjacent India, Nepal, Bhutan and parts of south-western China and Myanmar. Its 172 GBIF records concentrate in this native range, the British, Canadian, New Zealand and United States points reflecting its long cultivation as an ornamental rhododendron. It grows in subalpine and alpine shrubberies, on open rocky slopes, cliffs, forest margins and moist banks, typically between about 2700 and 3700 m. The plant photographed at Lachung in Sikkim at 3100 m in May illustrates the species flowering in late spring within the cool, humid montane belt of the Eastern Himalaya.
It is a small, aromatic, evergreen shrub with peeling, papery bark and elliptic to oblong leaves that are dark green above and conspicuously glaucous and densely scaly (lepidote) beneath, the source of the epithet glaucophyllum. The flowers are borne in small terminal trusses; the campanulate corolla is pink to rose, sometimes paler or white, with the calyx well-developed and lobed, a distinctive feature of the species. Ten stamens and a lepidote ovary are typical of its subgenus. The fruit is a small, scaly, dehiscent capsule releasing numerous tiny seeds.
The species belongs to Rhododendron subgenus Rhododendron, section Rhododendron (the lepidote, scaly-leaved rhododendrons), and within it to the glaucophyllum group, characterised by aromatic foliage and a prominent calyx. Several varieties have been recognised across its range. Widely distributed and locally common, and well established in cultivation, R. glaucophyllum is not considered threatened, forming an attractive element of Eastern Himalayan subalpine scrub.
Author: Rehder · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, The Rhododendron Handbook (RHS)