Sor'rel, the name of a genus of plants of the buckwheat family, common in Europe and America. The green foliage of all the species has a bitter taste and is used for medicinal purposes and in soup and salads. The plant grows about a foot high and has small red flowers. It is usually found in dry soil and in meadows and pastures, and some species, such as the field sorrel and the sheep sorrel, are very troublesome in fields. It is eradicated by means of cultivation and by the use of lime and other fertilizers in the soil. Other varieties of this plant are called red sorrel, sour weed and horse sorrel.