It is the dried leaves of some Cassia (leguminosae) species. These species are usually 60-100 cm high, yellow flowers, double hairy leaves and shrub-like shrubs. It grows wild in the semi-deserts and mountains of Northeast Africa and Arabia.
Cassia is basically a flowering plant belonging to the legume family. Cassia bears yellow, white and pink flowers. This shrub-derived senna is found in parts of North Africa, the Middle East, and Asia. It is found in Asia, mostly in the temperate regions of India and China. It is considered a powerful laxative due to the presence of compounds called anthraquinones.
Almost all parts of senna have medicinal value and have been used in herbal medicine in India for thousands of years. Its leaves have been used in traditional Chinese Medicine as an herbal laxative, but have been rendered unsuitable for regular use. Cassia is available at health food stores, in the form of capsules and tablets, and tea bags and liquid extracts. Undiluted dried roots of this plant can also be easily obtained. The legumes on senna also have a laxative effect, but they are less effective than the leaves.
NHS mentiones that there are many natural laxatives made from Senna that has many benefits.