Low to short, creeping, mat forming plant with short, non-flowering shoots. Leaves to 2.5 cm, roughly oval, alternate, toothed towards the apex. Flowers reddish purple, 9 to 12 mm long in dense clusters with petals erect.

Waste and rocky places often naturalised from gardens.

July and August.

Perennial

Scattered throughout most of Britain.

Occasional as a wild plant in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 10 of the 617 tetrads.