Clump to mat or colony-forming, spreading by short rhizomes, 10-30cm tall. Leaves 2-5cm long, ovate, entire or shallowly toothed, cuneate or rounded at the base, stalked, more or less hairy. Flowers 1-1.4cm long, violet, sometimes white or pink, summer and autumn. Northern hemisphere, in grassland, open woods, waste ground, lawns. Too invasive to be cultivated for ornament, especially on the rock garden. As might be expected of a species with such a wide geographic range, its basic characteristics vary from place to place and many botanical varieties and forms have been named.