Solved at last: The Philippine endemic Psychotria philippensis is a synonym of Scyphiphora hydrophylacea (Rubiaceae, Scyphiphoreae)

Abstract

Psychotria philippensis (Rubiaceae) was described by Chamisso and Schlechtendal in 1829, was the first Psychotria name published for the Philippines and is currently considered a Philippine endemic. The name remained in a taxonomic limbo for almost two centuries as it was variously accepted, synonymized or considered obscure, probably because the type specimen in the Berlin herbarium was destroyed and no original material has survived or is currently known. A combined analysis of the information on morphology, type locality and ecology contained in the protologue and a review of relevant literature on the study of the name by various authors over the last two centuries finally clarified the identity of P. philippensis. The name is confirmed here as a synonym of the rubiaceous mangrove Scyphiphora hydrophylacea, as first proposed by Schumann, one of the authorities of the family in the late 19th century, and the application of P. philippensis is fixed by neotypification. This reduces the number of Philippine species of Psychotria by one, but fortunately, this is not happening through extinction, as has been the case with too many species of the highly endangered Philippine flora. In addition, the history of the discovery and study of S. hydrophylacea and its synonyms are described in detail, and one lectotype and one neotype are designated.