Durazz.
Description
Albizia julibrissin, the silk tree or Persian silk tree, is a deciduous tree native from Iran and the Caucasus across to eastern Asia, now extensively planted and naturalised worldwide as shown by GBIF's more than 35000 occurrences spanning the United States, Korea, Japan, China, France, Turkey, Russia, Argentina, Italy and India among many others. In its Asian range it grows in warm-temperate broadleaf forest, open hillsides, valley margins and disturbed roadsides, from the lowlands to about 2500 m. The photographed tree from Wangdi Phodrang in Bhutan at 2000 m in May represents its occurrence in the warm inner Himalayan valleys, where it flowers in late spring and through the warm season.
It is a small, spreading tree with a broad, flat-topped, umbrella-like crown and smooth greenish-grey bark. The large, alternate leaves are bipinnate with numerous pinnae each bearing many small, oblong, asymmetric leaflets that fold together at night. The inflorescences are dense, hemispherical heads grouped in terminal panicles; the flowers are inconspicuous in their corollas but conspicuous through their numerous long, silky stamens, pink to deep rose distally and white below, giving a powder-puff effect. The fruit is a flat, papery, straw-coloured dehiscent legume containing several flattened seeds.
Albizia belongs to Fabaceae subfamily Caesalpinioideae (the mimosoid clade), characterised by actinomorphic flowers with showy stamens far exceeding the small petals. Nitrogen-fixing through root nodulation, fast-growing and widely cultivated as an ornamental, it has become invasive in parts of North America and elsewhere. Globally of Least Concern, it is valued horticulturally and ecologically as a pioneer of disturbed, well-drained, sunny sites.
Author: Durazz. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora Iranica, Nielsen revision of Albizia and allied Mimosoideae