Pollen morphology applied to species delimitation of Turkish <i>Dianthus</i> L. (Caryophyllaceae)

The pollen morphology of 89 taxa belonging to the genus <i>Dianthus</i> L. is considered, utilizing light, scanning and transmission electron microscopy, and the taxa are compared based on their pollen characters. Of these, the pollen morphology of 73 taxa is reported for the first time. Pollen grains of <i>Dianthus</i> taxa are spheroidal, polypantoporate and 29.1–53 µm in size, and have 12–24 prominent or sunken apertures uniformly distributed on their surface. Spinules were present on all pollen grains, and puncta were seen in 73 taxa. The exine surface ornamentation can be divided into three types, namely microechinate, microechinate-punctate or microechinate-punctate-foveolate. Cluster analysis and principal component analysis demonstrate that the clustering of <i>Dianthus</i> taxa studied does not correlate well with the sectional classification; rather, the punctum number, the pollen diameter and the spinule number are the most valuable variables for separating the examined taxa.