Senna (Senna alexandrina) is a small shrub in the Fabaceae family native to northeastern Africa and the Arabian Peninsula. It bears pinnate leaves, yellow flowers, and narrow pods, and the leaves and pods are the parts most often associated with traditional herbal use.
Historically, senna became well known as a strong herb used in measured amounts and specific preparations rather than as a gentle daily tonic. Because of its pronounced action, it is generally approached more cautiously than many ordinary household herbs.
