In this fifth volume of the Eisenack Catalog, New Series, we feature species whose descriptions were originally only in Spanish or Portugues. As well as documenting the original Spanish, the authors provide new translations for all diagnoses and descriptions. Under the present International Code of Botanical Nomenclature, each new name must be accompanied by a description or diagnosis in Latin or English. However, prior to 1996, there was not such provision: hence all the names with entries in this volume were validly published even though lacking a Latin or English description or diagnosis. The format in this volume remains unchanged from that of Volume 4.