oxalic acid (H2C2O4) /oksal″ik/ , a member of a family of dibasic acids found in many common plants, such as buckwheat, wood sorrel, and rhubarb. It is an important reagent and is used in bleaching and drying. Poisonous if ingested in excessive amounts, oxalic acid is used in veterinary medicine as a hemostatic. In dietary intake of foods containing oxalic acid, the substance binds with calcium and is sometimes found in renal calculi and the urine of patients with hyperoxaluria. Also called ethanedioic acid.
