(Benth.) Maesen
Description
Cajanus mollis (Benth.) Maesen is a trailing or twining legume distributed through the Himalaya and southern and southeastern Asia; GBIF records (about 161 occurrences) span India, Nepal, Bhutan, southern China, Thailand, Indonesia, the Philippines and Pakistan. It grows in open scrub, grassland, forest margins, hedgerows and disturbed slopes at lower and middle elevations, scrambling over surrounding vegetation. The plant photographed near Wangdi in Bhutan at 2700 m in September, flowering and fruiting late in the warm season, sits at the upper part of its altitudinal range in the warm-temperate hill belt, where open, sunny, well-drained slopes suit its sprawling habit.
It is a perennial herb or subshrub with slender, prostrate to climbing stems clothed in soft spreading hairs. The leaves are pinnately trifoliolate, the leaflets obovate to elliptic and densely softly pubescent, gland-dotted beneath, and subtended by small stipules. The flowers are papilionaceous, borne in short axillary racemes; the corolla is yellow, the standard often reddish- or purplish-veined on the outer face, with the keel enclosing the diadelphous stamens. The calyx is campanulate and hairy. The fruit is a flattened, oblong, pubescent pod constricted between the seeds and bearing oblique depressions on the valves, dehiscing to release several small seeds.
The taxon, formerly placed in the segregate genus Atylosia, was transferred to Cajanus by Van der Maesen, who united Atylosia with Cajanus on morphological grounds; it is one of the wild relatives of the cultivated pigeonpea, Cajanus cajan, and is therefore of interest as a genetic resource for crop improvement and disease resistance. As a nitrogen-fixing legume it enriches soil on disturbed ground. Widespread and adaptable, it is of least conservation concern across its broad Asian range.
Author: (Benth.) Maesen · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Van der Maesen revision of Cajanus, Annotated Checklist of the Flowering Plants of Nepal