The process of formation of megaspores from megaspore mother cell is called as Megasporogenesis. First of all a dome shaped outgrowth of undifferentiated, homologous and meristematic mass of cells is formed known as Nucellus. A cell just below the upper layer i.e., the epidermis, becomes visibly different from other cells and gets differentiated and increase in size. Due to the presence of a distinct nucleus, it looks different from the other cell. Now it is called as Archesporial cell. This Archisporial cell divides periclinally to form two different cells, the outer Primary Parietal cell and inner Primary Sporogenous cell. The Primary Sporogenous cell differentiate into Megaspore Mother cell (MMC). The Megaspore Mother cell further divide meiotically to form four haploid cells, the megaspores. The four haploid megaspore gets arranged in a linear fashion from chalazal to micropyler end. Out of the four haploid cell three present near the micropyle gets degenerate and only one which is near the chalaza remain functional. The chalazal megaspore which is functional, forms the female gametophyte.