The stems are erect and often have lilac hairs. Leaves ovate or elliptic-lanceolate, length1.5-5cm, width1-2.5cm, entire or sparsely serrate.
Cymes are terminal and spike-shaped; Bracts are kidney-shaped, the base is truncated or slightly heart-shaped, the top is long and tapering, and the back has coarse hair; Calyx is lip-shaped, with coarse hair in front and smooth back. The upper lip is oblong, 3-lobed, the two sides expand into semi-lanceolate, the lower lip is 2-lobed, the lobes are triangular, and the apex is acuminate. Corolla purple or white, lip-shaped, lower tubular, upper lip hat-shaped, 2-lobed, lower lip flat, 3-lobed; Stamens 4, 2 strong, filaments branched at the top, one end bearing anthers; Ovary 4-lobed, style filiform.
Nutlets are brown, rectangular and have three horns.