MICRO - MACRO MORPHOLOGY OF THE GENUS GEUM L. (ROSACEAE) IN IRAN AND THEIR TAXONOMIC SIGNIFICANCE

In the current survey, pollen, seed and fruit micro-morphological characters of the genus Geum L., comprising 5 species from two subgenera, Orthostylus Fisch & Mey. and Geum were examined using scanning electron microscope (SEM) and light microscope (LM). The pollen grains are monad, radially symmetrical, isopolar, tricolporate, medium in size, elliptical (from equatorial view) and triangular to circular (from polar view) in outline, subprolate to prolate in shape. The exine ornamentation is striate with micro perforation. Seeds coat micro -morphology revealed two types of sculpturing (including sulcat-ribbed and sulcat-foveolate) and fruits morphological analysis showed the importance of joint position and hairs on the style, beak length and hook in this genus. Principal component analysis (PCA) was carried out using a total of 20 characters. The result supports current classifications and emphasizes the importance of micro- macro-morphologocal traits for separating the two subgenera and species of the genus. Based on the important distinguishing characters a key is presented.