In the title xanthone derivative [systematic name: 9-hydroxy-5,10-dimethoxy-2,2-dimethyl-11-(3-methylbut-2-en-1-yl)-2,3,4,12-tetrahydro-1,7-dioxatetraphen-12-one], C₂₅H₂₈O₆, the xanthone ring system is roughly planar, with an r.m.s. deviation of 0.1038 (1) Å. The chromane ring is in a half-chair conformation and the 3-methylbut-2-enyl substituent is axially attached with an (+)-anticlinal conformation. Two weak intramolecular C—H...O interactions generate two S(6) ring motifs. In the crystal, molecules are linked into ribbons along the c axis by O—H...O and weak C—H...O hydrogen bonds. A π–π interaction, with a centroid–centroid distance of 3.5413 (8) Å, is also observed.