Splitting Echinocactus: morphological and molecular evidence support the recognition of Homalocephala as a distinct genus in the Cacteae
https://phytokeys.pensoft.net/article/26856/download/pdf/Według autorów Homalocephala to dobry rodzaj i obejmuje H. (echinocactus) texensis H. (Echinocactus) parryi i H. (Echinocactus) polycephala
