Buch.-Ham. ex D.Don


Description
A shrubby indigo widespread across the Himalaya and South to South-East Asia, native to India, Nepal, China, Bhutan, Myanmar, Thailand and Vietnam, with around 436 GBIF occurrences (numerous European and other records represent cultivated or herbarium material). It grows on sunny open slopes, scrub, forest margins, roadbanks and disturbed ground in the warm-temperate and subtropical zones, mostly between about 1200 and 2700 m. The featured plants were recorded in Bhutan in May and June, at Thimphu around 2230 m and the lower Mo-Chu valley at about 1550 m, both warm montane settings.
The species is a much-branched, erect to spreading shrub with slender, ribbed twigs bearing characteristic appressed, biramous (medifixed) hairs. The leaves are imparipinnate with numerous small, opposite, oblong to obovate leaflets that are sparsely strigose and minutely mucronate. Flowers are borne in slender, elongate axillary racemes; each papilionaceous flower has a small campanulate calyx and a pink to purplish-red corolla comprising a broad standard, two wings and a spurred keel, with diadynamous stamens. The fruit is a slender, straight, linear, terete to slightly compressed pod that splits along both sutures to release several small, cylindric seeds, the valves often twisting on dehiscence.
Accepted by POWO and GBIF, I. dosua belongs to the large, taxonomically complex genus Indigofera, distinguished from relatives by its leaflet number, indumentum and pod form. As a nitrogen-fixing legume it enriches poor montane soils and colonises disturbed sites, while its flowers attract bees. Widespread, adaptable and frequent in secondary habitats, it is of no conservation concern and is sometimes used locally for fodder, green manure and as a dye source.
Author: Buch.-Ham. ex D.Don · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Sanjappa monograph of Indian Indigofera



















