A flower is the reproductive component of a plant, and in addition to the accessory parts of sepals, petals, and nectar glands, it may contain one or both of the following: a stamen (the male flower part) and a pistil (the female flower part) (Figure 19).The male reproductive organ of a flower is called the stamen.It is made up of a pollen sac, also known as an anther, and a long filament that serves to sustain it.