The title compound, commonly known as (+)-(6aS,11aS)-medicarpin, C(16)H(14)O(4), was isolated from Dalbergia oliveri and displays a rigid mol-ecule consisting of four fused rings. The benzofuran system is inclined at an angle of 76.49 (2)° with respect to the chroman unit. The compound exists as a polymeric chain arising from inter-molecular O-H⋯O bonding.