Significance of Morpho-Palynological Diversity in Melliferous Plants in the Anzer Region (Türkiye) with Regard to Honey Authentication

Morpho-palynological studies are essential to distinguish the botanical and geographical origins of honey, ensuring its authenticity, quality, and commercial value. This study examined 64 melliferous plant species (including 6 endemics) from the Anzer Valley to characterize pollen morphology using light and scanning electron microscopy. Of these, 26 taxa were analyzed morphologically for the first time. The evaluation of the results revealed that among the 21 flowering plant families identified, Fabaceae is represented by the highest number of taxa, followed by Asteraceae, Lamiaceae, and Rosaceae. Palynological findings showed that plants with medium-sized pollen grains are the most dominant, followed by those with small-sized pollen grains, while plants with large-sized pollen grains are present in the lowest proportion. At the same time, tricolporate (59% species) was represented by more than half of the examined species. Also, the microechinate–perforate type was the most dominating exine ornamentation, contributing 13% of the total ornamentation, while reticulate–perforate and striate–perforate represented 11% each, respectively. A generalized linear mixed-effects model (the polar axis as the response, the equatorial diameter as the predictor, the taxon as a random intercept) revealed that pollen size variation was primarily species-specific. While 41 species showed a positive trend, four exhibited a negative one, and 19 showed no clear association. The overall fixed-effect slope was moderately positive and statistically significant (β = 0.50 ± 0.02 SE, p < 0.001). These results emphasize the morphological diversity among taxa rather than a single allometric pattern.