Taxonomic concepts, phenology and epiphytism: The case of Ceratozamia tenuis (Zamiaceae)

This study addresses the taxonomic identity of Ceratozamia tenuis (Dyer) D. W. Stev. & Vovides, 2016, a binomial that has been related historically with the taxonomic concept of C. mexicana Brongn., 1846. We describe the phenological stages of the C. tenuis, the reproductive period, and the degree of synchrony between males and females in natural habitat. Our results show that the reproductive period between pollen plants and ovulate plants is not synchronous. All ovulate plants in the populations studied emerge from August to October and exhibit the same time scale of growth, and thus their receptivity is synchronous. In contrast, pollen plants have a differential emergence period in the populations that lasts for more months and displays different growth rates. The correspondence in receptivity between pollen and ovulate occurs from January to March, but at the population level some pollen plants will continue their development and not reach maturity until July. In addition, we describe the recent discovery of epiphytism for the species; the epiphytic habit constitutes an ecological condition that had not previously been reported for the genus. Finally, we discuss the implications of these ecological features for dispersal.