The title compound, C(10)H(8)O(4), was isolated from the fermentation culture of the endophytic fungus Cephalo-sporium sp. In the crystal structure, mol-ecules are connected into a one-dimensional chain along [101] by inter-molecular O-H⋯O hydrogen bonds involving the hydroxyl and carbonyl functionalities. The chains are linked by non-classical C-H⋯O inter-actions, forming extended two-dimensional layers approximately parallel to (11).