The Caribbean genus Ginoria Jacq. (Lythraceae) is revised for the first time since a monograph was completed in 1903. Studies of the wood anatomy, vegetative and floral morphology, pollen and seed morphology, and chromosome numbers are summarized for Ginoria and the putatively closely related genera Crenea Aubl., Haitia Urb., Lawsonia L., and Tetrataxis Hook. f. Flowers of G. lanceolata O. C. Schmidt are described for the first time. Ginoria is minimally paraphyletic and possibly polyphyletic. Either Ammannia L./Nesaea Comm. ex Kunth or Lawsonia is sister to Ginoria based on ITS data. Phylogenetic analysis based on morphology finds Ginoria monophyletic only when Haitia is included in the genus. Phylogenetic analysis based on ITS sequences produced a single tree in which G. jimenezii Alain, a rare species from the Dominican Republic, is sister to the rest of the genus and Tetrataxis is nested within Ginoria. The positions of Haitia and Crenea remain to be tested by molecular data. Haitia is placed in synonymy of Ginoria based on the strength of the morphological evidence. Further taxonomic changes are deferred until more complete gene sampling among the putatively related genera is possible. Thirteen species of Ginoria are recognized: one from Mexico, six from Cuba, five from Hispaniola, and one from Puerto Rico and the Virgin Islands. The taxonomic treatment includes a key to the species, taxonomic descriptions, illustrations, and distribution maps. Ginoria sect. Discospermum Koehne is typified by G. curvispina Koehne. Three new combinations, G. buchii (Urb.) S. A. Graham, G. pulchra (Ekman & O. C. Schmidt) S. A. Graham, and G. americana Jacq. var. spinosa (Griseb.) S. A. Graham, are made. Two species are brought into synonymy: G. spinosa Griseb. and G. davisii M. C. Johnst. Evolution of selected characters and biogeography of the genus are briefly examined in a phylogenetic context. The endemic nature and rarity of the majority of species make them highly vunerable to extinction.