Critical evaluation of two published descriptions of the same species of Ceratozamia (Zamiaceae) from northern Oaxaca, Mexico, and the formal synonymization of C. martinezii under C. aurantiaca

The cycad species known in cultivation since the 1970s as Ceratozamia sp. ‘Presa Alemán’ was only recently described, as both C. aurantiaca Pérez-Farr., Gut.Ortega, J.L.Haynes & Vovides and C. martinezii Mart.-Domínguez, Nic.-Mor. & D.W. Stev. Because the two formal descriptions contain somewhat contradictory diagnoses, it became necessary to critically evaluate the two taxonomic treatments and clarify the discrepancies between them to allow for a clearer understanding of the species. A revised taxonomic treatment is herein provided, along with a proposal to formally synonymize C. martinezii under C. aurantiaca.