EN
The results of variability analysis of basal leaf epidermis stomata in the Caltha palustris L. complex are presented. Stoma length and width were measured in material from 17 Polish localities. In C. palustris subsp. laeta the stomata are clearly elongated and bigger (mean length 56.52 ± 8.41 µm) than those of subsp. palustris (mean length 46.80 ± 6.73 µm). Within the latter subspecies, in the sample determined as var. radicans they are only slightly longer (mean length 51.46 ± 5.46 µm) than wide (mean width 46.20 ± 5.25 µm), while in var. comuta they are distinctly longer (mean length 52.45 ± 5.17 µm) than wide (mean width 45.00 ± 3.86 µm); both, however, are more circular than in subsp. laeta.