(L.) W.T.Aiton
Description
Flemingia strobilifera is a widespread shrub of tropical and subtropical Asia, now pantropical through introduction, recorded from India, China, Nepal, Myanmar, Thailand, Taiwan, the Philippines, Malaysia, Indonesia, Papua New Guinea and numerous tropical American localities; its roughly 3874 georeferenced records make it by far the most abundantly documented species in this group. It thrives in open forest, scrub, grassland, roadsides and disturbed ground from the lowlands to about 1900 m. The plant photographed at Sitel in the Garhwal Himalaya at 1850 m, flowering in September, marks the upper subtropical edge of its Himalayan range.
It is an erect, branching shrub to about 1-2 m with finely pubescent, angled stems. The leaves are simple (not trifoliolate as in most relatives), ovate to elliptic, acuminate, with three prominent basal veins and entire margins. The species is at once recognised by its inflorescence: the small purplish papilionaceous flowers are enclosed within conspicuous, accrescent, folded and reniform bracts that overlap to form a cone- or strobilus-like cluster, hence the epithet strobilifera. The fruit is a small, inflated, two-seeded pod hidden among the persistent bracts.
Flemingia, of tribe Phaseoleae, is distinguished from Cajanus and allies by its glandular pods and, in this species, the showy enclosing bracts. F. strobilifera is highly variable and several infraspecific forms have been recognised. It is widely used in folk medicine and as a green manure and cover crop, and its nitrogen-fixing root nodules aid soil improvement on poor ground. A vigorous coloniser, it is locally regarded as weedy and is of no conservation concern.
Author: (L.) W.T.Aiton · Sources: POWO (Kew), GBIF, Flora of China, Flora of British India, Annotated Checklist of the Flowering Plants of Nepal, Mukerjee revision of Flemingia