Diploid populations of Valeriana officinalis L. (Valerianaceae) in Central Europe exhibit an extensive variation, with two conspicuous morphotypes. One, corresponding to the lectotype of V. officinalis, is larger, with broader, distinctly dentate leaflets, the other is in many respects similar to V. pratensis Dierb. and V. stolonifera Czern., but is glabrous, with narrow, usually entire leaflets. The two forms also differ in their ecological optimum and in geographical distribution, but are linked with numerous intermediates. Morphometric analysis (PCA) supports the picture outlined above. Nomenclatural analysis shows that the correct name for the taxon with narrow leaflets at the rank of variety is V. officinalis var. tenuifolia Vahl, with a very old synonym at the rank of subspecies, V. officinalis subsp. tenuifolia (Vahl) Schübler & Martens. A lectotype and epitype (from a plant with 2n = 14) are designated for this name. The epithet tenuifolia cannot be used for what has usually been called V. collina auct., or correctly, V. stolonifera subsp. angustifolia Soó. Further names were also studied in detail: V. officinalis var. angustifolia Wahlenb., V. officinalis var. angustifolia Hayne (for which a lectotype is designated), V. altissima Besser and V. officinalis var. altissima W. D. J. Koch.