Coutaportla, género endémico de México, Lorencea (Rubiaceae) endémico en Mesoamérica

Abstract

A new genus was described based on Portlandia guatemalensis Standl. of uncertain taxonomic position. The proposal of D. H. Lorence to place it into the genus Coutaportla Urb. as C. guatemalensis (Standl.) Lorence has not been supported by the discovery of a new species of Coutaportla (C. pailensis) nor by the molecular taxonomic studies of the group either. The differences of floral morphological, ovary and seed anatomical characters existing between the actually known three Coutaportla species of Lorence are the following: 1.) Placentation: all the three species belong to the Portlandia-complex (Urban 1923, Aiello 1979). Within the complex the placentation is one of the more important, fundamental feature in distinction and separation of the genera (Urban, 1923, Aiello 1979). Coutaportla has a unique form of placentation, the Coutaportla-type with a central-horizontal quadrangular placenta with determined number and position of ovules: 2–3 ascendent and 2–3 colgate separately positioned ones (Aiello 1979). This type of placentation is found only in Coutaportla ghisbreghtiana (the type species of the genus) and in C. pailensis. Coutaportla guatemalensis (Standl.) Lorence has a different form of placentation, with a basal-ascendent placenta and vertically arranged undetermined number of tile-likely arranged ovules, which is of Hintonia-type (Lorence 1986, Borhidi 2003). 2.) Morphological differences: five–six further important differences are found in the stipular, floral and seed morphology of the two Mexican (C. ghisbreghtiana and C. pailensis) and the one Mesoamerican (C. guatemalensis) species (Borhidi 2003, see below in the table). 3.) Molecular differences: the two species group have distant placements in the molecular cladograms of Chiococceae tribe belonging to two different major clades (Motley et al. 2005, Manns and Bremer 2010). All these differences seemed to give satisfactory amount of arguments for the separation of C. guatemalensis as an independent monotypic genus, the Lorencea Borhidi 2003, as endemic to the Mesoamerican flora, dedicated to the honor of D. H. Lorence, who has made numerous important discoveries and successful efforts to promote our knowledge about the Mexican and Central American Rubiaceae. The presented arguments convinced the experts of the World checklist of Rubiaceae to accept it as a valid new genus (Govaerts et al. 2006). As an obvious phytogeographical consequence of all these previous investigations, Coutaportla Urb. turned to be a Mexican endemic genus with two species living in the states Coahuila, Puebla and Oaxaca, of México and Lorencea Borhidi a monotypic endemic one of Mesoamerica, living in the states Chiapas of México and Guatemala. It was a surprise, that in the Flora Mesoamericana (2012): appeared the genus Coutaportla represented by C. guatemalensis (Standl.) Lorence, reducing Lorencea into synonymy with the following sentence: “No hay características de C. guatemalensis que apoyan su separación como género monotípico, como propuso Borhidi”, which is obviously an orbital lie with full knowledge of the above detailed facts. The treatment of the genus Coutaportla en la Flora Mesoamérica is a collection of inadmissible taxonomic inconsequences, starting with the modified generic protologue of Coutaportla by Ochoterena 2012 non Urban 1923, but attributed to Urban without amendment, which is a falsification of the original description of Urban based on a new type and including alien elements without new original studies (see Flora Mesoamericana 4.2: 69). Not to mention the absence of the obligatory citation of the criticised paper of Borhidi, and the fundamental publications of Aiello (1979), Motley et al. (2005), Borhidi (2006), and Manns and Bremer (2010). Therefore, the critical treatment of the genus Coutaportla with the re-establishment of Lorencea is a scientifically well-based, obvious, taxonomic necessity.