Karagain is a low, diffuse shrub, 15 to 30 centimeters or more in height. Leaves are 7 to 10 centimeters long, with 40 to 60 pairs of narrow leaflets, and a solitary, sessile gland on the rachis below the leaflets. Flowers grow one or two together in the axils of the leaves, shining, small and yellow. Pods are strap-shaped, flat, and about 5 centimeters long, containing rhomboid, dark-brown seeds.
In Japan, young stems and leaves are dried and used as a substitute for tea.
An aqueous extract from leaves, stems and pods called “hama-cha” is a conventional beverage in the San-in district of Japan.