The genus Zephyranthes is widely represented in Mexico, with 37 species of ornamental and medical importance. However, basic aspects of the genus, such as the environmental variables that determine its presence in certain sites, have not yet been addressed, which limits the knowledge of its ecology, potential applications and possible conservation strategies. Potential distribution models were generated with data on the presence of 13 species of the genus Zephyranthes, using 28 bioclimatic and edaphic variables with the maximum entropy method (Maxent). Of these variables, the most important and least correlated for each species were chosen by principal component analysis (PCA); the occurrence data were obtained from digital platforms and filtered to reduce spatial autocorrelation. The resulting models, had AUC values > 0.90 and Kappa index values > 0.6, in addition to being significant according to the results of the binomial test applied (p < 0.05). Maximum temperatures and humidity, as well as annual precipitation, are relevant environmental variables for the niche models. Most species are distributed in the biogeographic province of the Transmexican Volcanic Belt. Zephyranthes concolor and Zephyranthes lindleyana were the species with the largest potential range. The species with the most restricted potential distribution were Zephyranthes citrina and Zephyranthes sessilis. The most determinant variables for species with neotropical affinity are different from those identified for Nearctic species, reflecting niche differentiation, congruent with the evolutionary history of Zephyranthes.

Background: Neolloydia is a genus widely distributed in Mexico with notable morphological variation. In recent lists of Cactaceae, only Neolloydia conoidea has been recognized; however, previous reviews consider it to comprise a species complex. No studies have included statistical analyses of morphological variation, so species boundaries and recognition are uncertain. Questions: How many species should be recognized in the genus Neolloydia? Studied species: Genus Neolloydia Britton & Rose Study site and dates: Twenty-nine sites located in the Mexican states of Coahuila, Guanajuato, Hidalgo, Nuevo León, Querétaro, San Luis Potosí, Tamaulipas, and Zacatecas were explored between 2022 and 2024. Methods: Previous taxonomic proposals and a review of morphological traits allowed us to identify seven a priori groups. Ten quantitative and four qualitative traits were analyzed and tested using Random Forest classification analysis. Niche characterization was performed using GIS data (landform and soil type) from 189 records, followed by a chi-square goodness-of-fit test. Results: Random Forest classification analysis identified the seven a priori designated groups as independent. According to the chi-square goodness-of-fit test, the results are significant for landform and soil type. For two taxa, it was not possible to determine whether their distribution was non-random. Conclusions: A combination of morphological and niche characteristics supports the recognition of four species previously proposed by other authors; additionally, three new species are proposed.

Potential distribution models are used to predict the presence and geographic limits of a species as a function of bioclimatic variables. The lack of knowledge of the geographic distribution of species endemic to Mexico is a limiting factor in understanding their ecology, conservation, and potential applications. Distribution models were generated with occurrence data of 11 species of the genus Zephyranthes, 19 bioclimatic and three topographic variables with the Maximum Entropy (MaxEnt) method. The dimensionality reduction analysis (PCA) allowed determining that, of the 19 variables, four contributed the highest percentage to the classification of the models, explaining more than 80% of the accumulated variance. The resulting models were evaluated according to the value of the area under the curve (AUC) and potential distribution models with AUC values >0.89 were obtained. The results suggest that most species are distributed in the biogeographic province of the Transmexican Volcanic Belt. Zephyranthes concolor was the species with the largest potential distribution area. The species with the most restricted potential distribution was Zephyranthes sessilis.