Pollen morphology of Satureja L. (Nepetoideae, Lamiaceae) taxa in Türkiye

Seventeen naturally distributed Satureja taxa of the genus in Türkiye were used, using data obtained from scanning electron microscopy and light microscopy. Pollen grains of Satureja taxa, consistent with subtribe Menthinae, was identified as hexacolpate. The pollen size is small to medium, with the polar axis ranging between 24.00–38.00 µm, the equatorial axis between 28.00–43.00 µm, and the amb diameter also between 28.00–43.00 µm. The average exine thickness was calculated to be between 1.00–1.95 µm. The pollen grains of Satureja can be characterized by a bireticulate ornamentation. In the present study, the pollen morphology of 17 Satureja taxa was comprehensively examined, and the pollen features of 12 taxa—five of which are endemic to Türkiye—were characterized and reported for the first time. Based on pollen morphology, species were divided into two clusters, except for S. macrantha, S. boissieri, S. spinosa, and S. wiedemannia. It has been revealed that the amb diameter, equatorial and polar axis length play an important role in PC1, while the exine, sexine, and intine play an important role in PC2. Although there is no clear distinction between the two clusters, a correlation trend has been observed in the plant's habit and the number of flowers in the cymes.