A much-branched weed, often spreading in broad colonies in springtime; stems square; lacks a pleasant scent. Flowers in clusters above a dense canopy of massed leaves, rose-purple, trumpet-shaped with the typical mint-family lips. A white form is fairly rare. Blooms April-October. Leaves on long petioles, those subtending the inflorescence on short stems, heart-shaped, purplish- or bluish-green, wrinkled, with scalloped margins.
Similar species: Henbit (L. amplexicaule) is closely related and has many similarities. However, its foliage does not develop the pagoda-like or pyramidal shape that dead nettle's does. Instead, henbit's upper leaves look something like frilly collars around the stem.