Turnera diffusa, commonly known as damiana or Mexican holly, is a hardy flowering shrub that grows in the dry and sandy areas of U.S. Department of Agriculture hardiness zones 9 through 11. This evergreen plant sports small yellow flower buds and, with proper care, reaches heights between 2 and 6 feet. The sweet-smelling and disease-resistant damiana makes for a low-maintenance ornamental shrub or a fragrant addition to herb gardens, as it lends itself to teas and spices.