The pollen was prepared using the acetolysis method as described by Erdtman (1960).
The measurements and observations were carried out using both Light microscope (LM) and Scanning Electron microscope (SEM). For LM analysis, the acetolysed pollens were placed in a small vial,and 5-7 drops of silicone oil were added, and then the samples were mounted on a glass slide sealed with paraffin and observed under light microscope.