Ceratozamia oliversacksii (Zamiaceae), a new species of gymnosperm from western Oaxaca, Mexico

Phylotranscriptomics Shed Light on Intrageneric Relationships and Historical Biogeography of Ceratozamia (Cycadales)

“…Twenty-one species of Ceratozamia were divided into seven species complexes, based upon data from their geographic distribution, habitat preferences and gross morphology [ 30 ]. Later studies added several species to these species complexes [ 6 , 7 , 9 , 35 , 38 ]. Species of the Ceratozamia miqueliana complex and the Ceratozamia norstogii complex were grouped as two monophyletic subclades within the Miqueliana clade.…”

“…Due to improved diagnostic methods and genetic data, knowledge about the systematics of Mexican cycads has been expanded greatly, with the number of representative species increasing in recent years. More than 20 cycad species have been described from Mexico in the past few years [ 3 , 5 , 6 , 7 , 8 , 9 , 10 ]. Increased understanding of species phylogenetic relationships and their biogeographic distribution in time and space is crucial for their conservation in the region because the majority of cycad species are considered threatened [ 11 ].…”

“…(Zamiaceae, Cycadales), contains ca. 38 species including some recently described species from Mexico [ 1 , 4 , 5 , 6 ]. Species of Ceratozamia have their greatest diversity in cloud forests, oak forests, and tropical rain forests on karstic rocks in Mexico and similarly with the three species that occur in Guatemala, Honduras, and Belize.…”

“…In addition, some species diagnoses were based on geographical distribution and habitat differentiations, which is not a widely used approach and has limitations [ 4 , 31 , 32 ]. Several studies of the genus have evaluated the morphological variation among species populations with geographic and ecological affinities and, as a result, proposed the recognition of species complexes [ 6 , 7 , 18 , 33 , 34 , 35 , 36 , 37 ]. Additionally, morphological characters have been analyzed as quantitative and qualitative leaf morphological variations in the context of the species complexes [ 18 ].…”

Monograph of Ceratozamia (Zamiaceae, Cycadales): an endangered genus

“…Criteria to delimit species. The taxonomic treatment presented here is partly based on our previously published work on species complexes, considered from an integrative taxonomy perspective for corroboration or refutation of taxonomic hypotheses and employing the “taxonomic circle” sensu DeSalle et al (2005) , in which multiple data sources are analyzed independently for hypotheses testing ( Martínez-Domínguez et al 2016 ; 2017a , b , 2018a , 2020 , 2022a , b ). For taxa we have not treated previously, species were recognized by a unique combination of morphological characters evaluated at the population level, considering their biogeographic distribution patterns as an additional source of evidence.…”