Hamatocactus hamatacanthus var. davisii (Houghton & C.A.Armstr.) W.T.Marshall in Marshall & Bock, Cactaceae: 145. 1941
Hamatocactus hamatacanthus var. davisii in Marshall & Bock, Cactaceae: 145. 1941
is correct spelling for Hamatocactus hamatocanthus var. davisii in Marshall & Bock, Cactaceae: 145. 1941