Keys, distribution maps, habitats, references and nomenclature are given for 14 families of flowering plants occurring naturally or naturalized in Mississippi. Families included are: Aizoaceae, Balsaminaceae, Boraginaceae, Bromeliaceae, Burmanniaceae, Cactaceae, Commelinaceae, Cucurbitaceae, Dioscoreaceae, Passifloraceae, Plumbaginaceae, Primulaceae, Rubiaceae, and Valerianaceae.