Pollen and Seed Morphology of Tribulus Terrestris L. (Zygophyllaceae)

Light microscope (LM) and Scanning electron microscope (SEM) study of the pollen and seed morphology of Tribulus terrestris (Zygophyllaceae), especially in the native Bulgarian population from Thracian Lowland, was carried out. It was established that the pollen grains are oblate-spheroidal, radially symmetric, pantoporate. Exine ornamentation is reticulate. The seeds of Tribulus terrestris are flat, triangular-ovate. The seed sculpture corresponds to the Tubular-type, which is characterized with polygonal cells and straight arched anticlinal walls, whereas the periclinal ones are wavy with dense cuticular wax folds.