Echinocereus viridiflorus Engelm. subsp. viridiflorus Echinocereus viridiflorus Engelm. subsp. viridiflorus, Memoir Tour N. Mexico [Wislizenus]: 91. 1848 sec. Hunt 2016=Cereus viridiflorus (Engelm.) Engelm. in Mem. Amer. Acad. Arts, n.s., 4: 49. 1849 syn. sec. Guzmán & al. 2003