Echinocactus simpsonii var. minor Engelm. in Trans. Acad. Sci. St. Louis 2: 197. 1863
Echinocactus simpsonii var. minor in Trans. Acad. Sci. St. Louis 2: 197. 1863
is basionym for Echinocactus simpsonii f. minor, Handb. Kakteenkult.: 202. 1907
is basionym for Pediocactus simpsonii var. minor in Torreya 18: 180. 1918