Mammillaria insularis H.E. Gates Mammillaria insularis H.E. Gates in Cact. Succ. J. (Los Angeles) 10: 25. 1938 sec. Hunt 2016=Bartschella insularis (H.E. Gates) Doweld in Sukkulenty 3: 38. 2000 syn. sec. Guzmán & al. 2003