Straggling annual herb with a greyish bloom. Leaves often tendrilled and are twice-divided into wedge-shaped, 3-lobed leaflets; bears racemes of strongly 2-lipped pink flowers with broadly-winged flaring petals up to 10mm long.

Fruits are swollen and balloon-like, 20-30mm long.

Greek: cystis = the bladder; generally a bag, pouch; capnos = smoky; referring to the swollen, bladder-like capsules.

Latin: vesica = a bladder.