Sorrel. The prettier of the two groups of plants that are called sorrel is the little wood sorrel, or sour grass. It grows in shady woods, in lawns, and gardens throughout the Northern Hemisphere. It has dainty white or yellow flowers. Sometimes it is cultivated for its pleasantly acid, clover like leaves. These are used in flavoring soups, sauces, and salads. Usually, however, the sorrels used for flavoring are the larger plants with arrow shaped leaves. These latter sorrels belong to the buckwheat family. The best known are the common sorrel, which grows wild in meadows, the French sorrel, which is the species most usually cultivated, and the sheep, or red sorrel, which bears hundreds of tiny red fruits. Because its underground stems are wide spreading, it is a troublesome weed. It may be controlled, however, by cultivating the land and applying lime.