Most of the species of the family Rubiaceae with flowers arranged in head inflorescences are currently classified in three distantly related tribes, Naucleeae (subfamily Cinchonoideae) and Morindeae and Schradereae (subfamily Rubioideae). Within Morindeae the type genus Morinda is traditionally and currently circumscribed based on its head inflorescences and syncarpous fruits (syncarps). These characters are also present in some members of its allied genera, raising doubts about the monophyly of Morinda. We perform Bayesian phylogenetic analyses using combined nrETS/nrITS/trnT-F data for 67 Morindeae taxa and five outgroups from the closely related tribes Mitchelleae and Gaertnereae to rigorously test the monophyly of Morinda as currently delimited and assess the phylogenetic value of head inflorescences and syncarps in Morinda and Morindeae and to evaluate generic relationships and limits in Morindeae. Our analyses demonstrate that head inflorescences and syncarps in Morinda and Morindeae are evolutionarily labile. Morinda is highly paraphyletic, unless the genera Coelospermum, Gynochthodes, Pogonolobus, and Sarcopygme are also included. Morindeae comprises four well-supported and morphologically distinct major lineages: Appunia clade, Morinda clade (including Sarcopygme and the lectotype M. royoc), Coelospermum clade (containing Pogonolobus and Morinda reticulata), and Gynochthodes-Morinda clade. Four possible alternatives for revising generic boundaries are presented to establish monophyletic units. We favor the recognition of the four major lineages of Morindeae as separate genera, because this classification reflects the occurrence of a considerable morphological diversity in the tribe and the phylogenetic and taxonomic distinctness of its newly delimited genera.

The identity of the long-overlooked Ronabea morindoides and Patabea tenuiflora, synonymous with a species of Appunia (Rubiaceae). Candollea 76: 83-92. In English, English abstract. The identity of Ronabea morindoides A. Rich. has long been unclear and is here investigated. Two sheets of original material corresponding to this name are deposited in the General Herbarium of the National Museum of Natural History of Paris (P), and represent a mixed collection; one part of this material corresponds better with the description of this taxon and is more unambiguously identifiable, and is here designated the lectotype. With this typification, Ronabea morindoides represents a species of Appunia Hook. f. The identity of Patabea tenuiflora DC. has also remained uncertain since its description and is here clarified by studying the holotype in the Candolle Herbarium (G-DC); this is an additional synonym of R. morindoides. Taxonomic review of this group in the Guianas also finds that Ronabea morindoides is an older name for Appunia brachycalyx (Bremek.) Steyerm. and Appunia surinamensis Bremek. (Morindeae). Therefore, the new combination Appunia morindoides (A. Rich.) Delprete, C.M. Taylor & T. McDowell is here published. Received: August 15, 2020; Accepted: December 1, 2020; First published online: February 1, 2021