The hibiscus flower or callena sight here in Venezuela. Although it is quite widespread in the area, it is also highly appreciated; as I walk down the street or pass through various neighborhoods, there it is—displaying that pleasant red color (though other shades exist, red is the most popular).
In some cultures, it is used medicinally by preparing an infusion or tea from the flower. When the leaves are squeezed or crushed with water, they form a sticky paste that serves as a natural shampoo; while perhaps not as effective as store-bought varieties, it is certainly useful.
The leaves also serve as food for herbivores, such as sheep and goats. Additionally, the flowers can be used to polish casual shoes (made of semi-leather, leather, or rubber).
Finally, we must not forget that every plant plays a role in the ecosystem: they capture carbon dioxide through their leaves while producing oxygen, and they provide a habitat for various insects and birds.
Here is a photo of one of the flowers that I took with a borrowed camera; I hope you enjoy it.