Characteristic for the genus Mastersia are the indehiscent pods with seeds with elongated funicles. Within this genus only two species are recognized: M. assamica Benth. from Assam and M. bakeri (Koord.) Backer from Borneo, Celebes and the Moluccas. Both species are considered closely related; distinctive characters are found in the bracteoles, wing petals, keel petal and pod. Mastersia is placed within the Phaseoleae in the subtribe Glycininae-Glycinastrae. The distribution pattern of both species is discussed.