Phylogeny and generic limits in the sister tribes Psychotrieae and Palicoureeae (Rubiaceae): Evolution of schizocarps in Psychotria and origins of bacterial leaf nodules of the Malagasy species

Abstract

• Premise of the study: The pantropical, species-rich Psychotrieae and Palicoureeae are sister tribes of mostly drupe-bearing and nonbacterial leaf-nodulating species with problematic generic limits. This problem is more complicated in Psychotrieae due to the paraphyly of the genus Psychotria, the lack of diagnostic characters for some major lineages, and the poor sampling from some biodiversity hotspots. Schizocarps and bacterial leaf nodules have been used for recognizing formal groups in Psychotrieae, but their evolution and taxonomic value have not been studied using a robust phylogeny of the tribe.• Methods: We analyzed 287 samples from the entire ranges of the tribes, with particular emphasis on the Western Indian Ocean region, with the Bayesian Markov chain Monte Carlo method.• Key results: All allied Psychotria genera investigated are nested within a paraphyletic Psychotria. Schizocarps evolved independently two times within Psychotria, and one reversal back to the drupaceous condition is inferred. The Malagasy leaf-nodulated Psychotrieae (except Apomuria bullata) and the Comorian non-leaf-nodulated Psychotria conocarpa are nested within the (African) leaf-nodulated clade. Within Palicoureeae, Chassalia is paraphyletic with respect to Geophila sensu stricto, and the Malagasy Geophila gerrardii and the African Hymenocoleus are closely related.• Conclusions: A widely circumscribed Psychotria encompassing the entire Psychotrieae is supported. Within Psychotria, two separate origins of schizocarps from drupes, one reversal back to the drupaceous condition, and two independent origins of the Malagasy leaf-nodulated species are inferred. A new genus Puffia is described to accommodate Geophila gerrardii, and a narrow circumscription of Chassalia is adopted. Thirty-two new combinations, two lectotypifications, and 25 new names are presented.

The GenusPsychotria: Phytochemistry, Chemotaxonomy, Ethnopharmacology and Biological Properties

“…Sm., and Hydnophytum Jack genera, for example, were nested within Psychotria L. rendering the latter genus paraphyletic. 10 Before 2014, the relationships between among most members of tribes Psychotrieae and Palicoureae were still unknown partly, due to the poor or lack of sampling from some biodiversity hotspots. Schizocarpous fruits and bacterial nodules were used for recognizing authentic groups, but the evolution and taxonomic value of these characters have not been addressed based on a broadened sampling of the tribe.…”

“…Razafimandimbison et al 10 established that Psychotria includes all its allied genera, rendering the tribe Psychotrieae monogeneric. It was confirmed the paraphyly of Psychotria, because the genera Amaracarpus, Calycosia, Camptopus, represented by its type C. mannii (= P. camptopus), Dolianthus, Hydnophytum, Grumilea Gaertn., represented by the type G. nigra (= Psychotria nigra), Mapouria, and all the WIOR genera (Apomuria, Cremocarpon, Psathura, Pyragra, and Trigonopyren) are nested within a broadly defined Psychotria.…”

Nuevos resultados de la revisión taxonómica de los géneros Palicourea y Psychotria (Rubiaceae, Psychotrieae) en Cuba

“…separando la Palicourea s. l. con los géneros estrechamente relacionados (p.e., Margaritopsis, Notopleura, etc.) de la tribu Psychotrieae como una tribu hermana, "sister tribe" autónoma bajo el nombre Palicoureeae (Razafimandimbison et al 2014).…”

Chemical Constituents of Psychotria nemorosa Gardner and Antinociceptive Activity

“…8 The polyphyly of the genus has been demonstrated through recent worldwide molecular phylogenetic studies. Razafimandimbison et al 9 established that Psychotria includes all its allied genera, rendering the tribe Psychotrieae monogeneric. It is commonly used in folk herbal medicine for regulating menstrual disturbance, fever, against microbial infections, anti-inflammatory, analgesic, anticonvulsant, anti-rheumatic and even as cardiovascular, mental and eating disorders.…”