Taxonomy of Gentiana, section Pneumonanthae, in eastern North America

The taxonomy ofGentiana (Gentianaceae), sect.Pneumonanthae, in eastern North America is reviewed. Two species and one variety recognized in recent literature are reduced to synonymy, while one overlooked variety is restored to recognition. Distributional data include several reductions in range resulting from examination of previously misidentified specimens. Thirteen species are native to eastern North America; all are restricted to it. Of these, three are primarily prairie species; three, Appalachian; three, coastal plain; two, southern plateau; one, eastern boreal; and one, Great Lakes region to central boreal. Interfertility and occasional natural hybridization are present even among the most morphologically diverse species.