Mammillaria formosa Galeotti ex Scheidw. subsp. formosa in Bull. Acad. Roy. Sci. Bruxelles 5: 497. 1838 sec. Hunt 2016
- =Cactus formosus (Galeotti ex Scheidw.) Kuntze, Revis. Gen. Pl. 1: 260. 1891 syn. sec. Guzmán & al. 2003
- =Neomammillaria formosa (Galeotti) Britton & Rose, Cactaceae (Britton & Rose) 4: 90. 1923 syn. sec. Guzmán & al. 2003
- =Mammillaria neocrucigera Backeb., Cactaceae (Backeberg) 5: 3426. 1961 syn. sec. Guzmán & al. 2003
- =Mammillaria arroyensis Repp. in Kakteen And. Sukk. 40: 292. 1989 syn. sec. Guzmán & al. 2003