The main stem is greyish brown and the leaves are dark green and compound with leaflets, occurring in pairs of 4 to 7 plus a terminal one.
Flowers are small, pink or white and sweetly scented.
They are borne from December through to April in lovely dainty spikes up to 5cm long. Smooth, reddish-brown cylindrical pods with 8 to 10 seeds each, occur from May to July. These pods are presumably the basis of the specific name cylindrica. River indigo occurs naturally in riverine forest or scrub and on sandstone outcrops in Transkei and southern Kwazulu-Natal. Several species of butterflies including the common Lucerne Blue, Lampides boeticus , and the Drakensberg Blue, Lepidochrysops niobe , breed on members of the genus.