If you look inside a typical flower, you will see many small parts. The male reproductive part of a flower is called the stamen. It is composed of a long tube, called a filament, and has a pollen-producing structure on the end. This oval-shaped structure is called the anther.It is crucial in the reproduction of flowering plants, as it produces the male gametophyte, known as pollen.f you look inside a typical flower, you will see many small parts. The male reproductive part of a flower is called the stamen. It is composed of a long tube, called a filament, and has a pollen-producing structure on the end. This oval-shaped structure is called the anther.