Names and synonyms
Thelocactus macdowellii (Rebut ex Quehl) C. Glass, Cact. Suc. Mex. 14: 4 (1969).
Echinocactus macdowellii Rebut ex Quehl ('Mc. Dowellii'), Monatsschr. Kakt.-Kunde 4: 133-134 (1894). Echinomastus macdowellii Br. & R., Cact. 3: 151 (1922). Thelomastus Mac Dowellii Fric, in Kreuzinger, Verzeichnis 10 (1935), nom. inval. Neolloydia macdowellii H. E. Moore, Baileya 19: 166 (1975). Thelocactus conothelos var. macdowellii Glass & Foster ('mcdowellii'), Cact. Succ. J. (US) 49: 220 (1977). Thelocactus conothelos ssp. macdowelli var. sniceri Halda & Sladkovsky, Acta Mus. Richnov. Sect. natur. 7: 38 (2000).