Many flowers have evolved to be attractive to animals, so as to cause them to be vectors for the transfer of pollen. After fertilization, the ovary of the flower develops into fruit containing seeds. In addition to facilitating the reproduction of flowering plants, preserved flowers have long been admired and used by humans to bring beauty to the environment, and also as objects of romance, ritual, esotericism, witchcraft, religion, medicine, and as a source of food.