Prunella vulgaris, self-heal, carpenter's-weed, thimble flower, heart-of-the-earth
Heal All is a low growing, spreading, perennial of the mint family. It has very distinctive 'puckered' leaves with an opposite arrangement on square stems. Some burgeoning weed scientists use the 'pruned' texture of the leaves (think about you fingers after swimming) to remember the genus name Prunella. The ovate leaves (wider at the base and tapering toward the apex) are covered with short, coarse hairs. When viewing this plant from directly above, each set of leaves is rotated ninety degrees from the previous set.
Due to its low growth habit, heal all can often escape detection until firmly established in the lawn. Most often the first signs of invasion are during flowering when hundreds of purple 'pineapple-shaped' flowers are seen floating above the turf. Heal all produces these flowers in early-to-mid summer on stems that extend above the turf canopy.