Stachys officinalis, commonly known as Purple betony, Woo betony or Bishop's wort, is a perennial grassland herb growing to 70cm tall. Its leaves are stalked on upright stems, narrowly oval, with a heart-shaped base, with a somewhat wrinkled texture and toothed margins. The calyx is 5-7mm long, with 5 teeth, edged with bristles. The corolla 1-1.5cm long. Its upper lip flat, almost straight when seen from the side. The anthers stick straight out. It flowers in mid summer from July to September, and is found in dry grassland, meadows and open woods in most of Europe, western Asia and North Africa. In the British Isles it is common in England and Wales, but rare in Ireland and northern Scotland.