Stamen

The stamen is a male reproductive organ of a flower. It produces the pollen. The stamen has two parts: anther and stalk. The stalk is also called a filament.

The anther contains microsporangia. Each microsporangium contains pollen mother cells. These undergo meiosis, and produce pollen grains, which contain the male gametes (sperm).

The pollen grains are actually haploid male gametophytes.^[1]

The pollen is released by the opening of the anther. The pollen is carried by some agent (wind, or some animal) to the receptive surface of the stigma of the same or another flower. This process is known as pollination. After successful pollination, the pollen grain (immature microgametophyte) completes its development by growing a pollen tube and the two male gametes move through the pollen tube to the ovule.

1. ↑ This is to do with alternation of generations. All plants go through a cycle with a haploid gametophyte alternating with a diploid sporophyte. In the case of flowering plants the gametophyte stage is very small and brief.