A taxonomic study of the genus Delilia is presented. Two species are r
ecognized: D. biflora, a widespread weed of tropical and subtropical r
egions of the New World, extending from Mexico to northern Argentina a
nd recently introduced in the Cape Verde Islands; and D. repens, endem
ic to the Galapagos islands. A key to the species, illustrations, dist
ribution maps, and complete synonymy are presented.