Betony is a perennial that acts very much like an annual. It first appearsin cool, moist winter weather and spreads rapidly from underground white tubers. Leaves are opposite each other on a single, unbranched, square stem. They are broad at the base and taper to a rounded tip. Edges are serrated, or saw-toother. Like other members of the mint family, betony has trumpet-shaped, lavender flowers. As hot weather approaches, betony disappears, but tubers remain alive in the soil to produce new plants for the following year.