The concept common species exemplified from records of vascular plants in the Gaula valley area in Sør-Trøndelag, Norway

Alternative criterions for the concept common species in the Gaula area are discussed. Both administrative regional divisions, levels of altitude and grid squares were used. The species considered common were compared with the atlas showing the distribution of vascular plants in north western Europe by Eric Hultén (1971). For most species the accordance was good, a few species, however, defined as 'common 'by Hultén, were undoubtedly not 'common' in the area