Taxonomic significance of macro and micro-morphology of Geranium L. species Using Scanning Electron Microscopy

Macro and micromorphology of different parts that is, sepals, petals, flowers, indumentum, and leaf shape of 22 Geranium L. taxa from Iran were studied. These taxa representing the eight sections of the genus as sect. Dissecta, sect. Geranium, and sect. Tuberosa (of subgen. Geranium); sect. Batrachioidea, sect. Divaricata, sect. Lucida, sect. Ruberta and sect. Trilopha (of subgen. Robertium), that were collected from different geographical habitats of Iran. The biometric study involved 27 quantitative and 33 qualitative characters which were studied by use of stereomicroscopy and scanning electron microscopy (SEM). Statistical analyses were done by use of PAST software. Principal Component Analysis defined the most variable characters. Results showed that the diagnostic features were; length, width, apex of sepals, petals, trichomes type in pedicles and sepals along with their density, the shape length and width of leaves. In general, the present study revealed that the species could be differentiated by macro and micro-morphological characters. Taxa of two subgenera were clearly separated based on selected characters. These characters were found useful for the taxonomic identification and species delimitation in almost all taxa studied at the sub generic level, although some species of section Geranium and section Dissecta are mixed and nested in both subgenea.