Grusonia thurberi (Engelm.) G.D.Rowley in Tephrocactus Study Group 12(3): 45. 2006 Grusonia thurberi (Engelm.) G.D.Rowley in Tephrocactus Study Group 12(3): 45. 2006is new combination for Opuntia thurberi Engelm. in Proc. Amer. Acad. Arts 3: 308. 1856Taxon for this nameGrusonia thurberi (Engelm.) G.D.Rowley