The fresh root of Cochlearia Armoracia , Linn .
Petals obovate, obtuse, entire, claw-like.
History and Description. It flowers in June. The root is surmounted by several annulated heads. It breaks with a short fracture. Water, alcohol, or vinegar extracts its properties, which are due to the presence of a volatile oil, and which is dissipated by heat or desiccation.