Henna (lawsonia inermis) is a perennial tropical plant prized for its beautiful clusters of fragrant red, yellow, pink, or white flowers and leaves that can be crushed to create hair, fabric, and skin dye. In the United States, henna (also commonly known as Mehndi) can be grown outdoors in zones 9b-11. It also can be grown as a houseplant anywhere with plenty of sunlight and warmth