Pollen Morphology of the Genus Trigonella L. (Fabaceae) in Kurdistan / Iraq

Abstract
This study examines the pollen morphology of eight Trigonella species (Fabaceae) from Kurdistan Region of Iraq to clarify their taxonomic relationships. Using Light and Scanning Electron Microscopy, key traits such as pollen grain size, shape, aperture type, and surface ornamentation were analyzed. The results indicated that Trigonella pollen grains were predominantly monocolpate, tricolpate, or diacolpate, with triangular shapes in polar view and with variations in surface ornamentation which play an essential role in species identification. Surface ornamentation ranged from finely reticulate in T. filipes to coarse in T. spruneriana. The T. monspeliaca had the largest grain sizes (polar: 41.3 µm; equatorial: 40.93 µm) whereas T. foenum-graecum and T. filipes exhibited the longest colpi (22.13–22.34 µm), in contrast T. spruneriana displayed the coarsest surface ornamentation. Thus, these micromorphological differences serve as reliable characteristics for species identification and highlight adaptive divergence potentially linked to ecological and pollination strategies. The findings confirm the taxonomic significance of palynological data in distinguishing closely related Trigonella species