Native of Madagascar, this has naturalized itself around the world's tropics. Containing more than 70 alkaloid agents, this plant has been used to treat a host of ailments, including childhood leukemia, testicular cancer, Hodgkin's disease, diabetes, high blood pressure, and sore throats. Domesticated hybrid varieties of this species are often sold as annual bedding plants. This open pollinated species has dark glossy green leaves and rose-pink flowers to 1 1/2" across.