:1-naphthaleneacetic acid, referred to as NAA, is an organic compound (chemical formula: c10h7ch2co2h) that is a colorless solid readily soluble in organic solvents. Its structure was substituted with a carboxymethyl group at position 1 of naphthalene. It is a phytohormone, auxin, commonly used in commercial hair root meal or rhizogen, when plants are propagated using rooting. It can also be used in plant tissue culture.