Seed plants reproduce sexually through fertilization of male and female sex cells. There are two main types of seed plants: gymnosperms and angiosperms. Gymnosperms, such as pine trees, have cones as their reproductive structures and rely on wind to carry pollen from male to female cones for fertilization, which can take up to 15 months. After fertilization, an embryo develops into a seed within the female cone. When mature, the female cones open and release seeds which may grow into new trees. Angiosperms, including most flowering plants, produce colorful flowers to attract animals to assist with pollination and fertilization, allowing for more rapid reproduction than gymnosperms.