The anther is the part of the stamen where pollen grains are produced. It has microsporangia and has multiple layers surrounding the pollen sac. The pollen sac is the site for the production of the pollen grain. A typical microsporangium has four layers - Epidermis (outermost layer, function- protection), endothecium (hygroscopic in nature, function - promote dehiscence) followed by middle layers (function- protection) and tapetum (innermost layer, nutritive in function). The endothecium has fibrous thickening which again helps in the dehiscence and pollen dispersal.