Habitat: The temperate Himalayas from Kashmir to Bhutan, the Nilgiris, Khasi Hills and Travancore.
English: Tree-Rhododendron, Rose-Tree.Folk: Burans (Kumaon), Kurbak, Pullaas.Action: Leaf—anticephalalgic (applied to the forehead). Leaf and stem-bark—spasmolytic. Flowers— used in diarrhoea and dysentery.
The green leaves contain a gluco- side, ericolin. The extracts of leaves, stems and bark cause hypotension in cats and inhibit intestinal movements in rabbits. The acetone and chloroform extracts and a resinous fraction from the alcoholic extract of leaves depress respiration. The petroleum ether extract decreases the rate of heartbeat and contraction in isolated heart of frog.An alcoholic (50%) extract of the flowers lowered blood pressure in dogs and albino rats.Cyanidin-3-galactoside and cyani- din-3-arbinoside are present in the pigments of flowers. The leaves of var. nilgiricum and var. cinnamonum contain ursolic acid, friedelin, epifrie- delanol, quercetin. A triterpenoid, campanulin, has been isolated from the leaves of var. nilagaricum.