Annual herb 18–35 cm high; stems often purple, simple or branched, quadrangular, glabrous to ± ciliate on the angles. Leaves distantly placed, lanceolate, 11–28 mm long, 5–11 mm wide, sessile, apex obtuse or acute, margins shallowly dentate to subentire, 3-veined, ciliate on the veins and margins. Inflorescence capitate, terminal; flowers few to many, shortly pedicellate, with involucral bracts. Outer bracts 2, leafy, broadly lanceolate, up to 1 cm long, acute; inner bracts 2, broadly ovate, obtuse, toothed, cilate. Calyx ± 6 mm long, densely to sparsely pilose, lobes ± 2 mm, triangular, acute, ciliate. Corolla bright purple, ± 16 mm long, upper lip entire, lower lip 3-lobed with club- shaped hairs in the throat. Capsule cylindric-ellipsoid, ± 3 mm long, 1.5 mm wide.
