Thelocactus macdowellii (Rebut ex Quehl) Glass in Cact Suc Mex. 14: 3-5. 1969 sec. Hunt 2016
- ≡Echinocactus macdowellii Rebut ex Quehl in Monatsschr. Kakteenk. 4: 133. 1894 syn. sec. Guzmán & al. 2003
- =Echinomastus macdowellii (Rebut ex Quehl) Britton & Rose, Cactaceae (Britton & Rose) 3: 151. 1922 syn. sec. Guzmán & al. 2003
- =Neolloydia macdowellii (Rebut ex Quehl) H.E. Moore in Baileya 19: 166. 1975 syn. sec. Guzmán & al. 2003
- =Thelocactus conothelos var. macdowellii (Rebut ex Quehl) Glass & R.A. Foster in Cact. Succ. J. (Los Angeles) 49: 220. 1977 syn. sec. Guzmán & al. 2003
- =Thelocactus conothelos var. sniceri Halda & Sladk. in Acta Mus. Richnov., Sect. Nat., 7: 38. 2000 syn. sec. ???