There are two main types of seed plants - gymnosperms and angiosperms. Gymnosperms reproduce using cones instead of flowers and include cycads, ginkgos, conifers, and gnetophytes. Angiosperms are the largest group of plants and reproduce using flowers containing sepals, petals, stamens, and a pistil. Pollination occurs when pollen from the stamen sticks to the stigma on the pistil, and fertilization happens when the pollen joins with an ovule in the ovary. Seeds then develop inside the ovary and are dispersed in different ways depending on the plant.