Senna tea is derived from the leaves of Cassia plants, which comprise more than 250 different species. Senna has been traditionally used as a laxative as well as to clear the bowels before tests such as colonoscopy. The senna plants are small shrubs that bear yellow or green leaflets; these can be cultivated and dried to make senna tea. The two most popular senna leaf varieties are Cassia Angustifolia and Cassia accutifolia, which are exported around the world due to their unique health effects. Senna tea has a sweet flavor but has a slightly bitter taste in the end.