Mammillaria greggii (Engelm.) Saff. in Annual Rep. U.S. Natl. Mus. 1908: 531. 1909 Mammillaria greggii (Engelm.) Saff. in Annual Rep. U.S. Natl. Mus. 1908: 531. 1909is new combination for Mammillaria micromeris var. greggii Engelm. in Proc. Amer. Acad. Arts 3: 261. 1856Taxon for this nameMammillaria greggii (Engelm.) Saff.