Materials and methods
Plants used for the study came from all localities of D. affinis agg known in the Laska Upland. Examined 8 stands of ferns are isolated and very small only 1 or 2 individuals are noted in each of them (Woziwoda 2006). Used symbols of stands and detailed localizations are presented in Table 1 The 17 morphological characteristic features of individuals are described lamina shape, lamina base. la a texture, frond persistence, pinna shape in the mid blade, pinna-segment pinnulae) shape, pinna-segment apex, the lowest
pair of pinna-segment on each pinna, the lowest basiscopic pinna-segment on the lowest pinnae of frond, pinnapinna spacing; segment pinna-segment spacing, pinna-midrib base, stipe thickness, scale colour, scale shape. scale density and indusium shape, Morphological description of features in analysed specimens, named with letters from A to H, is summarised in Table 1. The sample is too scarce to make statistical analyses The classification offerns and nomenclature of D affinis group follow Fraser Jenkins (2007), A list of localities is given in ATPOL grid squares 1 x 1 km (Zajac 1978) and forest divisions. Herbarium sheets of plants are deposited in the (Herbarium Univers Lodziensis).