Rubiacearum Americanarum Magna Hama Pars XXXIV: The New Group Palicourea sect. Tricephalium with Eight New Species and a New Subspecies (Palicoureeae)

Many of the species classified in Psychotria L. subg. Heteropsychotria Steyerm. have been shown based on morphological and molecular characters to belong to Palicourea Aubl. (Rubiaceae, Palicoureeae), including the species of Psychotria ser. Appunianae Steyerm., Mapouria Aubl. sect. Nothocephaelis Mull. Arg., and Mapouria sect. Tricephalium Mull. Arg. Accordingly, these are transferred here to the new section Palicourea sect. Tricephalium (Mull. Arg.) C. M. Taylor, which includes 35 species found from southern Nicaragua to Bolivia and Paraguay, and is diagnosed by its rather thick-textured leaves with well-developed intersecondary veins that are extensively reticulated and inflorescences with the flowers sessile in small to large heads that are enclosed by well-developed bracts. The species are separated into three informal groups, the Palicourea conephoroides group, the Palicourea flaviflora group, and the Palicourea sessilis group. The following new species-level combinations are made here: Palicourea boyanii (Steyerm.) C. M. Taylor is based on Psychotria boyanii Steyerm.; Palicourea cenepensis (C. M. Taylor) C. M. Taylor is based on Psychotria cenepensis C. M. Taylor; Palicourea conephoroides (Rusby) C. M. Taylor is based on Cephaelis conephoroides Rusby; Palicourea costanensis (Steyerm.) C. M. Taylor is based on Psychotria costanensis Steyerm.; Palicourea crassifolia (Standl.) C. M. Taylor is based on Cephaelis crassifolia Standl.; Palicourea ernestii (K. Krause) C. M. Taylor is based on Cephaelis ernestii K. Krause; Palicourea flaviflora (K. Krause) C. M. Taylor is based on Uragoga flaviflora K. Krause; Palicourea heteroneura (Steyerm.) C. M. Taylor is based on Psychotria heteroneura Steyerm.; Palicourea hypochlorina (C. M. Taylor) C. M. Taylor is based on Psychotria hypochlorina C. M. Taylor; Palicourea jenmanii (Wernham) C. M. Taylor is based on Cephaelis jenmanii Wernham; Palicourea jervisei (Standl.) C. M. Taylor is based on Cephaelis jervisei Standl.; Palicourea kaieteurensis (Wernham) C. M. Taylor is based on Cephaelis kaieteurensis Wernham; Palicourea oleandrella (Standl.) C. M. Taylor is based on Cephaelis oleandrella Standl.; Palicourea ownbeyi (Standl. ex C. M. Taylor) C. M. Taylor is based on Psychotria ownbeyi Standl. ex C. M. Taylor; Palicourea pleiocephala (Mull. Arg.) C. M. Taylor is based on Psychotria pleiocephala Mull. Arg.; Palicourea schraderoides (K. Krause) C. M. Taylor is based on U. schraderoides K. Krause; Palicourea schunkei (C. M. Taylor) C. M. Taylor is based on Psychotria schunkei C. M. Taylor; Palicourea sessilis (Vell.) C. M. Taylor is based on Coffea sessilis Vell. (not Psychotria sessilis Vell.); Palicourea speluncae (Standl. & Steyerm.) C. M. Taylor is based on Psychotria speluncae Standl. & Steyerm.; Palicourea tepuiensis (Steyerm.) C. M. Taylor is based on Cephaelis tepuiensis Steyerm.; Palicourea triadica (Mull. Arg.) C. M. Taylor is based on Mapouria triadica Mull. Arg.; Palicourea tricephala (Mull. Arg.) C. M. Taylor is based on M. tricephala Mull. Arg.; and Palicourea zevallosii (C. M. Taylor) C. M. Taylor is based on Psychotria zevallosii C. M. Taylor. The following new names are published here: Palicourea arenosa C. M. Taylor replaces the name Cephaelis cuatrecasasii Standl. ex Steyerm.; Palicourea jungiana C. M. Taylor replaces the name Psychotria longipes Mull. Arg.; Palicourea perinsignis C. M. Taylor replaces the name M. insignis Mull. Arg.; and Palicourea yneziae C. M. Taylor replaces the name Rudgea mexiae Standl. The following new species are described here: Palicourea grandiceps C. M. Taylor is found in the Amazon basin in Colombia and Ecuador and has previously been confused with Palicourea arenosa; Palicourea lewisiorum C. M. Taylor is found in Amazonian Ecuador and Peru and has previously been confused with Palicourea flaviflora; Palicourea neillii C. M. Taylor is found in the mountains of southern Ecuador and is similar to Palicourea conephoroides; Palicourea oxapampana C. M. Taylor is found in central Peru and is similar to Palicourea sessilis (Vell.) C. M. Taylor; Palicourea paujilensis C. M. Taylor is found in south-central Andean Peru and is similar to Palicourea conephoroides; Palicourea simpsonii C. M. Taylor is found in southern Colombia and is similar to Palicourea triadica; Palicourea ucayalina C. M. Taylor is found in central Peru and is similar to Palicourea neillii; and Palicourea valenzuelana C. M. Taylor is found in central Peru and is similar to Palicourea conephoroides (Rusby) C. M. Taylor. One new subspecies is recognized here, Palicourea sessilis subsp. sororopanensis (Standl. & Steyerm.) C. M. Taylor, based on Psychotria sororopanensis Standl. & Steyerm. Lectotypes are designated for Mapouria sect. Tricephalium, Cephaelis conephoroides, Cephaelis ernestii, Coffea sessilis, Psychotria axillaris Vell. (hom. illeg.), Psychotria hancorniifolia Benth., Psychotria hancorniifolia var. angustifolia Mull. Arg., Psychotria hancorniifolia var. variifolia Mull. Arg., Psychotria interjecta Mull. Arg., Psychotria longipes, Psychotria pleiocephala, Psychotria transiens Wernham, U. flaviflora, U. schraderoides, and U. weberbaueri K. Krause.