The title compound [systematic name: 5,6,7-trimeth­oxy-2-(7-meth­oxy-1,3-dihydro-2-benzofuran-5-yl)-4H-chromen-4-one monohydrate], C20H18O8·H2O, was isolated from the popular Chinese medicinal plant Entada phaseoloides. In the crystal, inversion-related mol­ecules are joined by pairs of weak C—H⋯O hydrogen bonds. The dimers are further inter­connected by a bridging water mol­ecule via weak C—H⋯Owater and pairs of (O—H)water⋯O hydrogen bonds into a linear tape running parallel to the b axis.