Pentagonia plicatifolia (Rubiaceae, Dialypetalantheae) a new species from the Middle Magdalena Valley of Colombia, with a key for the Colombian species of the genus

Abstract We describe and illustrate Pentagonia plicatifolia A.F.Majín-L. & M.A.Jaram , a new species from the foothills and wet montane forest remnants (at elevations of 300–1,240 m) at Serranía de Las Quinchas, a region located in the Middle Magdalena Valley (the easternmost part of the Chocó Region), in the western slopes of the Eastern Cordillera of Colombia (Boyacá department). We compared this new taxon with morphologically similar species by leaf characters (color and shape) and flower size. Colombia is the country with the largest number of Pentagonia species, likely because three important centers of diversification converge: the tropical Andes, the Chocó region, and the northwestern Amazon. A key to the 22 Pentagonia species occurring in Colombia is also presented.