Stamens and carpels. Fluorescence micrograph of stamens (male reproductive structures, far left) and carpels (female reproductive structures, centre and right) from a thale cress (Arabidopsis thaliana) flower. Each stamen consists of an anther (rounded) on the end of a filament (long, thin). The anther contains the pollen grains (small, round) and releases them when mature. The carpel consists of a stigma (large, round) connected to the ovary (sausage-shaped) by a style. The ovary contains the ova (eggs).