Stamen. The stamen is the pollen-producing reproductive organ of a flower. Stamens typically consist of a stalk called the filament, and an anther, which contains microsporangia. Anthers are most commonly two-lobed and are attached to the filament either at the base or in the middle portion.tamen. The stamen is the pollen-producing reproductive organ of a flower. Stamens typically consist of a stalk called the filament, and an anther, which contains microsporangia. Anthers are most commonly two-lobed and are attached to the filament either at the base or in the middle portion.