Notes on Some South American Species of Psychotria Subgenus Heteropsychotria (Rubiaceae), with Observations on Rubiaceous Taxonomic Characters

During the preparation of a treatment of the Rubiaceae for the Guide to the Vascular Plants of Central French Guiana, several field and laboratory observations have contributed toward a better understanding of the morphological variation of certain species of Psychotria and have stimulated a reevaluation of some morphological features used by previous authors in distinguishing taxa in the Psychotria. Typification for all taxa is provided, several new synonyms and one new combination, Psychotria carapichea (Poir.) Delprete, are proposed, and illustrations of P. ligularis and P. carapichea are included.