Mammillaria nana subsp. duwei (Rogoz. & P.J.Braun) Pilbeam, Cactus File Handb. 6: 203. 1999 Mammillaria nana subsp. duwei (Rogoz. & P.J.Braun) Pilbeam, Cactus File Handb. 6: 203. 1999is new combination for Mammillaria duwei Rogoz. & P.J.Braun in Kakteen And. Sukk. 36: 164. 1985Taxon for this nameMammillaria nana subsp. duwei