Hook. f.
Description
Rhododendron maddenii is a temperate Himalayan and Indo-Burmese species native from India and Bhutan through China to Myanmar and Vietnam; GBIF's 432 records also reflect its wide cultivation, with occurrences logged from New Zealand, Australia, Britain, Japan, Korea, Malaysia and the United States. In the wild it grows on steep, often rocky and humus-rich slopes, cliff ledges and the margins of temperate broadleaf and conifer forest, frequently as an epiphyte or lithophyte. The figured plants from Lachen in Sikkim at 2760 m and Paro in western Bhutan at 2400 m, both flowering in June, place it firmly within the cool temperate forest belt where summer monsoon moisture and high atmospheric humidity prevail.
It is an evergreen shrub or small tree, the bark smooth and peeling in papery flakes. The leaves are leathery, elliptic to oblong-lanceolate, dark green and glabrous above, the undersurface densely covered with brown lepidote scales characteristic of the subgenus. The flowers, borne in terminal trusses of few blooms, are large, funnel-form to tubular-campanular and strongly fragrant, white often flushed with pink and scaly on the outside of the corolla tube. There are typically numerous stamens and a long style, the ovary lepidote. The fruit is an elongate, scaly, dehiscent capsule releasing many small seeds adapted to wind and epiphytic establishment.
Within Rhododendron subgenus Rhododendron, R. maddenii belongs to the large, taxonomically complex subsection Maddenia, distinguished by lepidote foliage and showy scented corollas, and it shows considerable variation in size and indumentum across its range. The fragrant, pale flowers attract long-tongued moths and other nocturnal pollinators. Long prized in horticulture, it is the source of many hybrids; in the wild it remains generally secure, though habitat loss and over-collection threaten some local populations.
Author: Hook. f. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, The Genus Rhododendron (Royal Horticultural Society), Cullen's revision of lepidote Rhododendron