Many of the species classified in Psychotria L. subg. Heteropsychotria Steyerm. have been shown to belong to Palicourea Aubl. (Rubiaceae, Palicoureeae), including the species of Psychotria sect. Nonatelia (Aubl.) Müll. Arg., based on morphological and molecular characters. Accordingly, these along with several additional species are transferred to the new section Palicourea sect. Nonatelia (Aubl.) C. M. Taylor. This new section includes 26 species found from southern Mexico to Trinidad and northern Argentina, and is diagnosed by its stipule morphology, distinctive leaf venation, and inflorescence arrangement. This new section includes Palicourea racemosa (Aubl.) Borhidi, Palicourea woronovii (Standl.) C. M. Taylor, Bruniera & Zappi, Palicourea veracruzensis (Lorence & Dwyer) Borhidi, and 23 additional species with names newly published here. The following new combinations are made here: Palicourea amita (Standl.) C. M. Taylor is based on Psychotria amita Standl.; Palicourea apiculata (Müll. Arg.) C. M. Taylor is based on Psychotria apiculata Müll. Arg.; Palicourea brevicollis (Müll. Arg.) C. M. Taylor is based on Psychotria brevicollis Müll. Arg.; Palicourea carnosocarpa (Dwyer & M. V. Hayden) C. M. Taylor is based on Psychotria carnosocarpa Dwyer & M. V. Hayden; Palicourea eggersii (Standl.) C. M. Taylor is based on Psychotria eggersii Standl.; Palicourea fissistipula (Müll. Arg.) C. M. Taylor is based on Psychotria fissistipula Müll. Arg.; Palicourea forsteronioides (Müll. Arg.) C. M. Taylor is based on Psychotria forsteronioides Müll. Arg.; Palicourea malaneoides (Müll. Arg.) C. M. Taylor is based on Psychotria malaneoides Müll. Arg.; Palicourea mamillaris (Müll. Arg.) C. M. Taylor is based on Psychotria mamillaris Müll. Arg.; Palicourea minutiflora (Müll. Arg.) C. M. Taylor is based on Psychotria minutiflora Müll. Arg.; Palicourea obconica (Müll. Arg.) C. M. Taylor is based on Psychotria obconica Müll. Arg.; Palicourea octocuspis (Müll. Arg.) C. M. Taylor is based on Psychotria octocuspis Müll. Arg.; Palicourea soejartoi (C. M. Taylor) C. M. Taylor is based on Psychotria soejartoi C. M. Taylor; Palicourea stenostachya (Standl.) C. M. Taylor is based on Psychotria stenostachya Standl.; Palicourea subfusca (Müll. Arg.) C. M. Taylor is based on Psychotria subfusca Müll. Arg.; Palicourea tacarcunensis (Dwyer) C. M. Taylor is based on Psychotria tacarcunensis Dwyer; Palicourea tsakiana (C. M. Taylor) C. M. Taylor is based on Psychotria tsakiana C. M. Taylor; and Palicourea valerioana (Standl.) C. M. Taylor is based on Psychotria valerioana Standl. Five new species are described here: Palicourea cajamarcana C. M. Taylor is found in Andean northern and central Peru and has previously been confused with Palicourea amita; Palicourea dodsoniana C. M. Taylor is found in lowland western Ecuador and has previously been confused with Palicourea stenostachya; Palicourea locellata C. M. Taylor is found in Andean eastern Colombia and has unusual tubular stipules and chambered pyrenes; Palicourea meieri C. M. Taylor is found in the mountains of Venezuela and has previously been confused with Palicourea eggersii; and Palicourea topoensis C. M. Taylor is found in Andean Ecuador and northern Peru and has previously been confused with Palicourea amita. Lectotypes are designated for three series, Psychotria ser. Stenothyrsae Müll. Arg., Psychotria ser. Spicatae Müll. Arg., and Psychotria ser. Stachythyrsae K. Schum.; for three subseries, Psychotria subser. Quadricuspides