Oxalic acid structured oxalic acid, namely oxalic acid, the simplest ErYuanSuan. It is generally colorless transparent crystal, harmful to human body, can make the person inside the ph of the lost balance and influence on children's development, oxalic acid plays an important role in the industry of oxalic acid can derusting. Oxalic acid around in nature, often in oxalic acid salt forms exist in FuNiu flowers and plants like sheep hoof grass, sorrel and acid mould grass membrane, almost all the plants containing calcium oxalate.