Indigofera

Indigofera is a genus of annual and perennial herbs, shrubs and undershrubs in the Fabaceae family. The plants are mostly covered in forked hairs on stems and leaves.

The leaves are simple, scale-like or pinnate, comprising three to nine leaflets. The leaflets are more often opposite than alternate, their margins entire. The stipules are hair-like to leaf-like, while stipels, secondary stipules, are often present at leaflet bases.

The inflorescence is an axillary or stem-tip spike or raceme, sometimes on long peduncles with bracts that sometimes persist. The calyx usually has a bell-shaped tube with lobes that are about equal. The flower colours are often shades of pink, the petals sometimes deciduous.

The banner petal is usually sessile with hairs on its outside. The pair of lateral wings may be clawed, eared or hunched. The keel has a short, broad claw. It is sometimes dilated into a sac or spur and has a prominent hair fringe along its upper margin.

The stamens are joined in a tube with the one nearest the banner separate. The anthers are pointed. The ovary is mostly sessile comprising one to many ovules. The style is usually bent at a right angle, the stigma capitate.

The fruit is a variable, wide or narrow pod, globose or linear, coiled or straight and sometimes hairy. The seeds are separated inside the pod by dividing walls or septa. The seeds are globose to cylindrical, sometimes compressed or ellipsoid.

There are about 730 Indigofera species widespread in tropical and subtropical areas, 210 of which occur in southern Africa.

Plant parts of several species, including the roots, have featured in traditional medicine or still do. The leaves of some species yield indigo, used as a dye.

The plant in picture is Indigofera obcordata (Leistner, (Ed.), 2000; Vlok and Schutte-Vlok, 2015; Manning, 2007; Van Wyk and Gericke, 2000).