is a tree or large shrub, reaching a height of up to 15 feet, and comparable in diameter. Trunks are up to one inch across, with upright branches bearing many leathery, evergreen leaves, which are compound; one terminal leaflet and three to five pairs of side leaflets. The leaflets are rounded at the top, tapering at the base, have entire edges and are generally hairless. The bark is black or dark grey, smooth on new growth, gradually becoming shredding, and split by shallow grooves.
Flowers are produced in dense clusters at the end of the branches, containing between 5 and 15 heads. Flowers have a dull purple calyx with a felt-like surface texture, five purple petals and ten stamens, all separate. The banner petal has a broad notch at the tip, a groove down the middle, and flecks of dark purple at the center. The fruit is a swollen, hanging pod, up to 2 inches long, narrowed between each seed.