In the crystal structure of the title compound, 3,4,5-trihydroxybenzoic aci
d monohydrate, C7H6O5.H2O, the gallic acid molecule is essentially planar a
nd has two intramolecular hydrogen bonds between hydroxyl groups. The H ato
ms of the three hydroxyl groups are oriented in the same direction around t
he ring, and form intra- and intermolecular hydrogen bonds. The crystal str
ucture is stabilized by all available intermolecular hydrogen bonds, includ
ing also those involving the water molecule.