is a vine; stems are sender, branched and up to 4 feet long, usually growing along the ground or on top of other plants. The dark green, somewhat shiny leaves are relatively large, borne at quite widely spaced intervals; they are trifoliate, with three approximately triangular leaflets which, like the stems, have a sparse covering of short hairs, some of which are minutely hooked. Leaflets are often indented along the two long sides, and may be lobed.
Flowers are produced in small numbers on stalks up to 4 inches long, from the leaf nodes; they have a small, purplish-green calyx with tiny lobes, and a longer, deep pink corolla which has five petals; a wide, slightly cupped banner, two flat wings angled downwards, and the keel petals fused and twisted two or three times to form a short spiral. The fruit is a gently curved, lightly hairy green pod, up to 2 inches long. The plant can be in bloom any time of the year, though late summer is the peak season.