Mammillaria brachytrichion Lüthy Mammillaria brachytrichion Lüthy in Kakteen And. Sukk. 38: 295. 1987 sec. Anderson 2001=Mammillaria pennispinosa subsp. brachytrichion (A. Lüthy) U. Guzmán in Cactaceae Syst. Init. 16: 18. 2003 syn. sec. Guzmán & al. 2003