Hoary Vervain, a native perennial, grows up to three feet tall. It generally has a two to five-inch spike of purple, tube-like, 1/2-inch flowers, but it can have multiple flower stalks. The two to three-inch oval leaves are thick and covered with hairs. They are also coarsely toothed and pointed. Hoary Vervain grows best in dry fields, ditches, shores and roadsides. (July)