Hibiscus is a natural diuretic that contains vitamin C and minerals. It's traditionally been used as a mild medicine.
Roselle (Hibiscus sabdariffa) is a species of Hibiscus thought to be native to West Africa.
Hibiscus, specifically roselle, has been used in folk medicine as a diuretic and mild laxative.
In 2015, the Journal of Hypertension stated Hibiscus provides a reduction in blood pressure.