This figure of a mature flower identifies individual flower parts. Figure by Mariana Ruiz, available on Wikipedia.

Pollination is defined as the transfer of pollen, containing the male gametes, from the anther of a flower to the stigma, the female part of the flower. But just what are an anther and a stigma? Use the diagram above and the definitions below to help unlock the secrets to how pollination occurs.

The flower is the reproductive part of a plant that contains the male pollen and/or the female ovule. It consists of the calyx on the outside, the corolla lying inside the calyx, the stamens enclosed by the corolla, and the pistil in the center of the flower. The outermost whorl of a flower, called the calyx, is made up of small green leaf-like structures at the base of the flower called sepals. The calyx encloses and protects the inner whorls. Inside the calyx is the corolla, the whorl made of petals that protects the stamen and pistil. Petals serve to attract pollinators, as they are often brightly colored and sometimes scented and nectar producing. Collectively, the calyx and the corolla are called the perianth. The male reproductive part of the plant is the stamen. The stamen produces pollen grains and is made up of the filament and anther. The anther is the pollen bearing portion of the stamen and the filament bears and supports the anther. The innermost whorl is the pistil, the female reproductive part of the plant. It consists of the ovary, style, and stigma. The ovary contains the ovules and matures to become a fruit. The style bears the stigma, the receptive surface for pollen grains. Ovules contain an egg cell and, after fertilization, develop into a seed.

Additional flower parts are the pedicel, the flower stalk; the nectary, a gland-like organ that secretes nectar; the floral axis, the flower stem containing reproductive organs; articulation, the space on a stem between two nodes; and microsporangium, the structure producing microspores.