Echinocereus scheeri (Salm-Dyck) Scheer [ Echinocereus scheeri variety gentryi (Clover) N.P.Taylor]
Echinocereus scheeri (Salm-Dyck) Scheer [Cactaceae]
W. Curtis, Bot. Mag., ser. 2, vol. 1(): : t. 19 (1984)