Hook. f.
Description
Rhododendron pendulum is an epiphytic or epilithic dwarf shrub of the humid Eastern Himalaya, with verified occurrences in China, India, Bhutan and Nepal (further GBIF records from Britain and the United States represent cultivated stock). It is most characteristic of cool, mist-laden temperate forest, where it perches on mossy trunks, branches and rock faces, generally between about 2700 and 3700 m. The Bhutanese material illustrated, from the Tumching-La between roughly 3000 and 3500 m in April and May, captures the species in flower at the close of the cold season in its typical cloud-forest setting.
It is a small, straggling shrub with thin, often pendulous branches densely clothed, like the young growth and leaf undersides, in a soft rusty-brown woolly indumentum. The small, elliptic to oblong leaves are leathery, with revolute margins, dark green and somewhat rugose above and thickly tawny-tomentose beneath. The flowers are borne few together at the branch tips; the corolla is broadly campanulate to rotate, white sometimes flushed pink, and comparatively large for so diminutive a plant. The fruit is a small ovoid capsule that splits septicidally to shed numerous minute seeds adapted to dispersal in the canopy.
Rhododendron pendulum belongs to subgenus Rhododendron, section Pogonanthum and its allies, distinguished by its woolly indumentum and epiphytic habit, and was described by J.D. Hooker from his Sikkim explorations. Its dependence on permanently humid, moss-rich forest makes it a sensitive indicator of intact cloud-forest conditions, and although not presently regarded as threatened, it is vulnerable to forest degradation and to disruption of the orographic mist regime on which its epiphytic lifestyle depends.
Author: Hook. f. · Sources: POWO (Kew), GBIF, Flora of Bhutan, The Genus Rhododendron (Royal Botanic Garden Edinburgh), Flora of China