The family Leguminosae is one of the largest families of flowering plants with members widely distributed throughout the world. The characteristic feature of the family is the fruit which is a pod. The family is divided into three sub-families (Mimosoideae, Caesalpinoideae and Papilionoideae) according to the form of the flower. This key deals with the sub-family Papilionoideae which has pea-like flowers with five sepals, five petals, ten stamens and one carpel. Common plants of the Papilionoideae in New Zealand include clovers, medics, peas, beans, gorse, broom, lupins and the native Kowhai.