The known morels in Mexico, a description of a new blushing species, Morchella rufobrunnea, and new data on M-guatemalensis

A critical analysis of the known species of Morchella from Mexico, including M. angusticeps, M costata, M. elata, M. esculenta (M. conica; M crassipes, M rotunda), M. guatemalensis and M. umbrina, is presented. In addition, M. rufobrunnea is described as a new species from the State of Veracruz. Morchella rufobrunnea belongs to the blushing species, a fourth group of species in the genus proposed by the authors. The blushing species also include M. guatemalensis and M. rigidoides, and all three species are confined to the tropics or subtropics. Morchella rigidoides is known only from New Guinea, and M. guatemalensis only from Guatemala and Mexico. The new species differs in the form and color of the ascomata, length of the alveolae, and the color of staining. A revision of the microscopic features of M. guatemalensis is made based on recent collections from Mexico and Guatemala. After a comparison of the asci, ascospores and paraphyses of M. guatemalensis with those of M rufobrunnea and other close species, it is concluded that microscopic features, except the width of the paraphyses in some cases, are not important in the taxonomy of the genus. The form and color of the ascomata, the position of the ribs, the length of the alveolae, and the staining are the most important taxonomic features in Morchella. A key to the seven known species of Morchella in Mexico is presented.