Echinocactus pygmaeus Speg. in Anales Mus. Nac. Buenos Aires, ser. 3, 4: 497. 1905
Echinocactus pygmaeus in Anales Mus. Nac. Buenos Aires, ser. 3, 4: 497. 1905
is basionym for Frailea pygmaea, Cactaceae 3: 210–211. 1922
is basionym for Astrophytum pygmaeum in Acta Mus. Richnov., Sect. Nat., 12(1): 14. 2005