Zygocarpum caeruleum

Zygocarpum caeruleum is a species of flowering plant in the family Fabaceae. It is found only in Yemen. Its natural habitats are subtropical or tropical dry forests and subtropical or tropical dry shrubland.

Habitat
Common in semi-deciduous woodland and shrubland, mainly on the limestone plateaus but also occurs on granite in the Haggeher mountains (Socotra Island). Altitude of (50–)200–800 m.

Recognized by the violet-blue flowers. Usually a slender tree or shrub but can be prostrate in windswept places on the limestone plateau. However, it is easily recognized, even when not in flower, by the distinctive purplish black line along the midrib on the undersurface of the leaflets.