Hook.f.
Description
Spiraea micrantha is a deciduous shrub of the temperate forests and forest margins of the eastern Himalaya, native to Nepal, Bhutan, India and adjacent China, with around 208 documented occurrences (records from Britain and North America representing cultivated material). It grows in open mixed and conifer forest, woodland edges, scrub and along streambanks, typically between about 2500 and 3300 m. The photographed plant was recorded at Chogcham in Bhutan at 3000 m, flowering in June, when these mid-montane shrubs come into bloom at the start of the summer growing season.
The species is a much-branched shrub with slender, arching, glabrous to thinly pubescent reddish-brown branches. The leaves are alternate, simple and ovate to elliptic-lanceolate, acuminate at the apex and serrate to doubly serrate along the margin, glabrous or sparsely hairy and somewhat glaucous beneath, on short petioles. The inflorescences are lax, terminal, leafy-based corymbose panicles of numerous small flowers (the epithet micrantha denoting the small blooms); each flower has five rounded white to pinkish petals, a shallow campanulate hypanthium, and numerous exserted stamens longer than the petals. The fruit is a cluster of small, glabrous, dehiscent follicles.
Spiraea, of the family Rosaceae and subfamily Amygdaloideae (tribe Spiraeeae), is a north-temperate genus of ornamental shrubs; S. micrantha belongs to the group of Himalayan species with terminal panicle-like inflorescences, distinguished by its small flowers and acuminate, sharply serrate leaves. As a forest-margin shrub it is insect-pollinated and contributes to montane understorey structure. Widespread across the eastern Himalaya and locally common, it is not considered to be of conservation concern.
Author: Hook.f. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, A Monograph of the Genus Spiraea