Dendrophylax porrectus is a leafless epiphytic orchid occurring in Florida (U. S. A.), the Greater Antilles, Mexico, Guatemala, and El Salvador. Previous morphological and phylogenetic analyses revealed considerable variation across its geographic range. This study examines morphological and molecular variation among populations of D. porrectus. Phylogenetic analyses of sequence data of nuclear (nrITS) and plastid (matK, ycf1) regions revealed several well-supported clades within D. porrectus. Molecular data and morphometric analyses of root thickness and floral parts support the recognition of two species within the D. porrectus clade. Dendrophylax megarhizus is described as a new species from Campeche, Jalisco, Veracruz, and Yucatán states of Mexico. A key to the species of Dendrophylax is presented.