Synonyms
Echinocactus macdowellii Rebut ex Quehl
Echinomastus macdowellii (Orcutt) Britton & Rose
Thelocactus conothelos var. macdowellii (W.T.Marshall) Glass & R.B.Foster
Neolloydia macdowellii (Rebut ex Quehl) H.E.Moore
Thelocactus multicephalus Halda & Panar.