Spider lily flower stamen. Coloured scanning electron micrograph (SEM) of a cilia (hair-like structures) from a spider lily flower (Hymenocallis sp.) stamen. Stamen are a plant's male reproductive structures. They produce and release the male gametes (sex cells), pollen grains. The pollen grains fertilise ovaries, the female gametes. Cilia grow on the filament (stalk) of the stamen. It is thought they have a sensory function. Magnification: x215 when printed at 10 centimetres wide.