The lilac to mauve flowers of Millettia grandis grow in many-flowered stem-tip spikes, above the leaves. The narrow inflorescences become about 25 cm long. The flower stalk and calyx are densely covered in brown, velvety hairs.

Flowering happens in summer, sometimes only midsummer, emerging from rusty brown buds (Coates Palgrave, 2002; Pooley, 1993; www.plantzafrica.com).