Tropical hibiscus plants rarely fruit, at least in my experience. But you can cross-pollinate their flowers by using a little moist paintbrush, like from a child’s watercoloring set. If you’re lucky, a knobby green fruit will develop from the base of the mother flower. With further luck, the fruit will ripen and dry up, yielding a few dark, hard seeds.
The bloom in the photo (and click it for a bigger look) is a cross between Madame DuPont of the DuPont Nursery, and Chariots of Fire by Hidden Valley Hibiscus. Plant breeders tend to name their best creations, and who am I to blow against the wind? This one is called Miss Emily.