1. Laboratory of Phytogeography and Applied Geobotany, Section Environment and Landscape, Department of PDTA, Via Flaminia 72, 00196 Rome, Italy
2. Centro de Investigación Científica de Yucatán, A. C. Calle 43 No. 130 Col. Chuburná de Hidalgo, CP 97200 Mérida, Yucatán, México