Rubiacearum Americanarum Magna Hama Pars XXXVII: The New Group Palicourea sect. Chocoanae of the Chocó Biogeographic Region, with Two New Species (Palicoureeae)
Psychotria L. subg. Heteropsychotria Steyerm. has been shown, based on morphological and molecular analyses, to be polyphyletic. Most of its species, including its type, belong to Palicourea Aubl. Several Psychotria species studied here are related to species of Palicourea ser. 11 and are transferred here to Palicourea. Palicourea ser. 11 is formally described here as Palicourea sect. Chocoanae C. M. Taylor, except for four of its former species that are excluded. Palicourea sect. Chocoanae includes 15 species from Central and South America and is centered in the Chocó biogeographic region of northwestern South America and eastern Panama. Palicourea sect. Chocoanae includes eight species already classified in this genus: Palicourea acanthacea (Standl. ex Steyerm.) C. M. Taylor, Palicourea deneversii (C. M. Taylor) Borhidi, Palicourea dimorphandrioides (Dwyer) C. M. Taylor, Palicourea frontinoensis Cogollo & C. M. Taylor, Palicourea grandistipula (Standl. ex Steyerm.) C. M. Taylor, Palicourea orquidea C. M. Taylor, Palicourea sopkinii C. M. Taylor, and Palicourea tamaensis (Standl. & Steyerm.) Steyerm. Four more species transferred into this genus have new nomenclatural combinations made here. Palicourea cotejensis (Standl.) C. M. Taylor is based on Cephaelis cotejensis Standl.; Palicourea plusiantha (Standl.) C. M. Taylor is based on Psychotria plusiantha Standl.; Palicourea timbiquensis (Standl.) C. M. Taylor is based on Psychotria timbiquensis (Standl.) C. M. Taylor; and Palicourea trianae (Standl.) C. M. Taylor is based on Cephaelis trianae Standl. One species, Palicourea psilophylla (Steyerm.) C. M. Taylor, was previously treated as a variety, Palicourea tamaensis var. psilophylla Steyerm. Two species are newly described here: Palicourea mistratoana C. M. Taylor is found in western Colombia and differs from Palicourea sopkinii in its smaller leaves, inflorescences, and bracts; and Palicourea shuar C. M. Taylor is found in southern Ecuador and differs from Palicourea sopkinii by its corymbiform inflorescences and shorter bracts. A lectotype is designated for Cephaelis grandistipula Standl. ex Steyerm.