... Alders ( Alnus Mill.) are the common trees in Europe and Asia, and there are some taxonomically interesting forms on the border of the area. ... We have checked mentioned hypotheses using multivariate methods based on classic morphometrics data and two variants of geometric morphometrics of alder leaf. ... On the contrary, A. barbata must be considered as separate species. Our data show that the results of geometric morphometrics and classic morphometrics could be significantly different. ...