Four New Species of Gentianella (Gentianaceae, Gentianeae, Swertiinae) from Peru, with a Review of the Taxonomy of the Genus
Four new species of Gentianella Moench (Gentianaceae, Gentianeae, Swertiinae) are described from Peru. Gentianella bussmannii J. S. Pringle, from Amazonas Department, is characterized by nodding flowers with red corollas 20--50 mm, with the lobes about as long as or slightly shorter than the tube, and linear, apically acuminate leaves densely spaced proximally, gradually more widely spaced distally. Gentianella empetroides J. S. Pringle, from La Libertad Department, is similar to G. quipuscoana J. S. Pringle, differing in its glabrous stems, smaller leaves, and larger flowers in more compact clusters. Gentianella nephostelium J. S. Pringle, from Amazonas Department, is characterized by a stout stem with a persistent basal rosette of thick leaves and numerous flowers with white, campanulate corollas, proximally with purple veins, 18--25 mm, with obovate lobes ca. 3 times as long as the tube. Gentianella yanachagensis J. S. Pringle, from Pasco Department, is probably gynomonoecious, at least in the larger plants, and is characterized by creeping, vinelike stems, widely spaced, lanceolate leaves, and flowers with white to pale violet corollas 8--16 mm, with the lobes slightly shorter than the tube. The taxonomic history of Gentianella, including its distinction from related genera, exclusions based on phylogenetic studies, and infrageneric divisions that have been proposed, is reviewed.