EN
Pollen morphology and pollen variability of Rubus gracilis were studied. A total of 260 grains from 13 natural Polish localities were examined. Important characteristics include: a stretched bridge; a visible pore area and endopores; ectocolpi arranged regularly, more or less evenly spaced or, more rarely, joining one another in the apocolpium, long (79.3% length of the polar axis) and narrow; exine sculpture striate, distinct; striae and muri of equal width, rather narrow; striae usually running parallel to the polar axis, sometimes forming semicircles in the apocolpium zone; with distinct perforations. The size, outline and shape turned out to be poor criteria when identifying the species. A statistical analysis of 10 quantitative grain characteristics showed their little variability. The highest variability was found to occur in two traits connected with d (the distance between the apices of two ectocolpi). Statistical studies revealed no differences among the grains from the individual localities, likely the result of apomixis.