Flowers of prunella vulgaris
consist of a hooded upper lip above a larger, three-lobed lower lip, the middle section of which is delicately fringed. The reddish-brown calyx, below the petals, is also lobed, and bristly. Flowers form an elongated cluster (2 inches tall) but only a small number bloom at any one time, so the most visible components are the calyxes. The tough stems are square in cross-section and also bear long, stalked leaves. The common name self-heal refers to the ability of the plant to heal wounds; the leaves have also found use in tea-making, and as a salad ingredient.