Bisexual flowers are the flowers which has both the essential whorls, i.e., androecium and gynoecium, including stamens , carpels and an ovary. This kind of flowers can undergo self-pollination. A dioecious or unisexual flower bears either male or female sex organs. The plant could be either male or female. When only stamens are present, it is called as staminate flower. When only carpels are present, it is called as pistillate flower.