"Echinocactus" . . "Echinocactus polycephalus Engelm. and Bigelow" . . "Caryophyllales" . "Cottontop Cactus" . . "Magnoliophyta" . . . "Engelm. and Bigelow" . "Echinocactus polycephalus" . "Cactaceae" . "Plantae" . . . . . . . . . . "Magnoliopsida" . .