Echinocactus horizonthalonius subsp. diabolicus Halda, L.Vacek & Vaško in Acta Mus. Richnov., Sect. Nat., 13: 1. 2006 Echinocactus horizonthalonius subsp. diabolicus Halda, L.Vacek & Vaško in Acta Mus. Richnov., Sect. Nat., 13: 1. 2006Taxon for this nameEchinocactus horizonthalonius subsp. diabolicus Halda, L.Vacek & Vaško