(Vol. 07, 2004-12) A New Species of Mortoniodendron (Malvaceae Sens. Lat.) from the Rain Forests of the Isthmus of Tehuantepec, Mexico

The taxonomic history, defining characters, and relationships of the genus Mortoniodendron are briefly sketched. Characters that define M. pentagonum, a species known from a limited area in Guatemala, are elaborated. A closely related but distinct species from Veracruz, Mexico, M. uxpanapense Dorr & T. Wendt, is described and illustrated. The new species is considered to be Critically Endangered (CR) under the IUCN red list classification.