The anther is a part of the stamen, which is the male reproductive part of a flower. It is the top, bulbous portion of the stamen and is where the male gametophytes, or male reproductive cells, are produced in a flower. The anther is usually borne at the tip of a long, slender stalk known as a filament. It consists of two lobes that each house a pair of pollen sacs (microsporangia) that produce pollen for pollination. As the anther matures, the partition between the adjacent microsporangia of a pair breaks down so that there are only two pollen-containing sacs (one in each lobe of the anther) at the time the anther releases the pollen. During the process of fertilization, pollen lands on the stigma, a tube grows down the style and enters the ovary. Male reproductive cells travel down the tube and join with the ovule, fertilizing it. The fertilized ovule becomes the seed, and the ovary becomes the fruit.