In the Know Senna (sometimes called cassia) is a member of the legume family, identified by its narrow leaves and vivid yellow blossoms. There are several species of senna found throughout the tropical regions of the world, but the most common variety cultivated by humans is Senna alexandrina, also called Egyptian Senna. Senna is often used today in landscaping for its appealing flowers. During much of history, senna was a valuable cash crop in Egypt, harvested either for its seedpods, or for the leaves, which were used to craft this traditional herbal tea. A Powerful Herbal Tradition The senna tea tradition goes back hundreds of years. More recently, studies have revealed that senna tea is a natural source of amino acids, flavonoids, mucilage and volatile oils, able to, when used as directed, safely help regulate the bowels. Some caution must be used, however, when drinking Senna Tea; this herb is a well-known and potent non-prescription laxative.