Greek ēōs ‘dawn’ and Eocene + Opuntia, called by Chaney “the dawn cactus of the Eocene”. A fossil plant originally thought to be an Opuntia-like cactus, but now considered a member of the family Cyperaceae. Sometimes incorrectly called Euopuntia(Greek eu- ‘true’).
Maarten H.J. van der Meer (2023 Dec 06). Eopuntia. Dictionary of Cactus Names. Retrieved from https://www.cactusnames.org/Eopuntia