The Sorrel (Rumex acetosa) belongs to Polygonaceae (the Knotweed family). It is a perennial herb that is native to Japan and the temperate region of Northern Hemisphere. This herb grows in rice field linches or grasslands and can reach 30-80 cm in height. The basal leaves are oblong with long petioles. The panicles are borne on the stem apices and bloom reddish tinged small flowers from May to August. It is dioecious. The plant contains oxalic acid and has a sour taste.