Research Information System
Palynology, 2026 (SCI-Expanded, Scopus)
This study provides the first comprehensive comparative palynological assessment of Turkish Clinopodium taxa. Despite the recognized diagnostic value of palynological traits in Lamiaceae, their contribution to infrageneric classification in Clinopodium has not been comprehensively evaluated for the Turkish taxa. Three taxa treated in Davis’s Flora of Turkey–(Clinopodium umbrosum (M.Bieb.) K.Koch., C. vulgare subsp. arundanum (Boiss.) Nyman, and C. vulgare subsp. vulgare L.)–were comparatively analyzed with the recently described Turkish endemic C. hakkaricum Dirmenci and Fırat. Both qualitative (pollen shape, exine ornamentation, aperture type, and lumen morphology) and quantitative (polar and equatorial axes, colpus length and width, exine and intine thickness) pollen parameters were evaluated by light and scanning electron microscopy. All examined taxa possess hexacolpate apertures, although considerable variability in pollen shape was observed (oblate, oblate-spheroidal, perprolate, prolate, prolate-spheroidal, subprolate). Lumen morphology was generally irregular. Based on quantitative data, C. hakkaricum typically exhibited the maximum quantitative values (polar axis: 41.24 ± 4.18 µm; equatorial axis: 44.17 ± 5.31 µm; intine thickness: 0.62 ± 0.19 µm; colpus length: 29.47 ± 3.99 µm; colpus latitude: 0.85 ± 0.53 µm), whereas C. vulgare subsp. arundanum displayed the minimum values (polar axis: 26.53 ± 6.09 µm; equatorial axis: 20.66 ± 2.90 µm; colpus length: 19.26 ± 8.06 µm). The cluster analysis based on principal component analysis (PCA) revealed a clear separation of the studied Clinopodium taxa into two major groups, indicating substantial morphological divergence among them. The clustering pattern also suggests that C. umbrosum and C. vulgare subsp. vulgare are more closely related to each other than to the other taxa, while C. vulgare subsp. arundanum represents the most divergent taxon. Among the analyzed traits, quantitative parameters (particularly polar and equatorial axis lengths and colpus metrics) accounted for the highest proportion of variance in the PCA and displayed the strongest discriminatory power.