It is a perennial herbaceous plant, with elliptic, obtuse leaves. It grows as a vine or creeper, doing well in moist, neutral soil. The most striking feature about this plant are its vivid deep blue flowers; solitary, with light yellow markings. They are about 4 cm long by 3 cm wide. There are some varieties that yield white flowers.
The fruits are 5 – 7 cm long, flat pods with 6 to 10 seeds in each pod. They are edible when tender.