Variation in Potentilla sect. Aureae (Rosaceae) in the Baltic states

The morphological variation of four Baltic representatives of the genus Potentilla section Aurea–P. neumanniana, P. arenaria, P. subarenaria and P. crantzii was studied with multivariate methods. Altogether 41 characters were used. The most important characters for the phenetical classification are those of the epidermis: characters of stellate and glandular hairs and numbers of cells. Macromorphological characters are less important, the most useful of these being the length of sepals and stipules and the number of teeth of the central leaflet. All four species are significantly distinct. Even P. subarenaria, a putative hybrid of P. arenaria and P. neumanniana, is clearly separated. At the same time, the species are morphologically quite variable, and it is possible to distinguish subclusters (morphotypes) within P. neumanniana, P. subarenaria and P. crantzii, which are also statistically distinct. The varieties described by Wolf (1908) under the name P. verna (P. neumanniana) do not agree well with the morphs in our material. However, it can be admitted that var. typica and var. neumanniana axe prevalent, var. pseudo-incis? and var. incis? occur occasionally; only var. longifoli? can be quite clearly delimited.