Echinocactus papyracanthus (Engelm.) Engelm. in Trans. Acad. Sci. St. Louis 2: 198. 1863
Echinocactus papyracanthus in Trans. Acad. Sci. St. Louis 2: 198. 1863
is new combination for Mammillaria papyracantha in Mem. Amer. Acad. Arts, n.s. 4(1): 49. 1849