Ferocactus emoryi subsp. rectispinus (Engelm. ex J.M. Coult.) N.P. Taylor in Cactaceae Consensus Init. 6: 16. 1998 sec. Hunt 2016
- ≡Echinocactus emoryi var. rectispinus Engelm. ex J.M. Coult. in Contr. U.S. Natl. Herb. 3: 362. 1896 syn. sec. Hunt & al. 2006
- =Ferocactus rectispinus (Engelm.) Britton & Rose, Cactaceae (Britton & Rose) 3: 134. 1922 syn. sec. Hunt & al. 2006
- =Ferocactus emoryi var. rectispinus (Engelm. ex J.M. Coult.) N.P. Taylor in Bradleya 2: 37. 1984 syn. sec. Hunt & al. 2006