Justicia gendarussa, commonly known as willow-leaved justicia (Marathi:बाकस, bakas, काळा अडुळसा, kala adu****; Sanskrit:कसनः, kasanah, वैध्यसिंहा, vaidyasinha), is a small erect, branched shrub, endemic to India.

It is useful in asthma, rheumatism and colics of children. It may have the potential to be the basis for a birth control pill for men. Clinical tests are being conducted in Indonesia.