Turbinicarpus rioverdensis Holotype: Mexico, San Luís Potosí: near Río Verde, 1989, J. Jauernig 64 (WU) Holotype: Mexico, San Luís Potosí: in declivibus petrosis prope Cerritos, solo calcareo, alt. 1600 m, 15 Apr 1992, H. Swoboda s.n. (PR: 11712)