Differentiation between Carex arenaria L. populations at the eastern range margin based on female and male glumes variation

480 spikes from 16 populations of Carex arenaria L. planted in an experimental garden were collected and analysed for 4 female and 4 male glumes each. The characteristic of the interpopulational differentiation on the area of Poland was based on multivariate analysis, Student t-test and the coefficients of variation. The separateness of three populations from the isolated inland stations - 3(Góra), 11 (Tuczno), 15 (Poznań) and individual character of - 2 (Wisełka), 6 (Sobieszewo) from the coast and 9 (Ołobok) from Lower Silesia is shown. The lowest level of variation and in consequence a particular usefulness for taxonomic considerations have two characters - a and a' (length of female and male glumes). The obtained pattern of interpopulational differentiation may be caused by various factors - migration routes on the Polish territory; selection pressures associated with different ecological conditions present in fixed dunes along the Baltic Sea coast and in isolated inland stations, occupied by C. arenaria; reduction of an extensive primary populations to markedly smaller isolated subpopulations