Ormosia limae (Leguminosae, Papilionoideae, Sophoreae s. 1., Genistoid clade) is described and illustrated as a new species of Ormosia sect. Unicolores. It resembles the Amazonian species O. holerythra, but is morphologically and geographically distinct. The relationship of O. limae along with O. holerythra clearly lies with species of Ormosia sect. Unicolores because of the shared distinctive four to nine pairs of arcuate secondary leaflet veins, fruits that are dehiscent and glabrous at maturity, and seeds that are uniformly red in color and with a small, ca. three mm long, elliptic hilum. An identification key to sect. Unicolores is provided in order to enumerate all of the constituent species and to suggest relationships among them. Ormosia limae is known only from few collections in the Atlantic forest of southern Bahia, Brazil.