Morphological similarities among the 24 species of Amphitecna currently recognized A dendrogram based on the results from an UPGMA analysis B main flower types found in Amphitecna, flowers with a transverse fold in the corolla throat (Amphitecna costata, top right) and flowers radially symmetric, without a transverse fold in the throat (Amphitecna tuxtlensis, bottom right). Photographs by Hector Gómez Domínguez (A. costata) and Pablo Carrillo Reyes (A. tuxtlensis). NM = Northern Mesoamerica; SM = Southern Mesoamerica.