The title compound, C(18)H(16)O(7)·H(2)O, is a flavonoid isolated from Dodonaea viscosa-. The benzopyran ring system of the flavonoid is essentially planar [maximum deviation = 0.025 (2) Å] and inclined at 5.83 (2)° to the attached benzene ring. The water of hydration is involved in extensive hydrogen bonding, assembling the mol-ecules into a supra-molecular network via classical inter-molecular O-H⋯O hydrogen bonding. The crystal structure is further stabilized by π-π stacking inter-actions [centroid-centroid distance between benzene rings = 3.564 (3) Å].