Morning glory pollination. Coloured scanning electron micrograph (SEM) of a morning glory (Ipomoea sp.) flower pistil (fringed lobes) with attached pollen grains (round). A pistil is the female reproductive structure, which is composed of one or more carpels. Carpels bear the reproductive organs: stigma, style and ovary. The ovules in the ovary are fertilised by the pollen, which contain the male sex cells. Each carpel may then ripen to produce a seed-bearing fruit.