X-ray powder diffraction data, unit-cell parameters, and space group for tectoridin, C22H22O11, are reported [a = 13.577 (2) Å, b = 10.466 (8) Å, c = 9.454 (7) Å, α = 85.709 (4)°, β = 94.855 (3)°, γ = 101.485 (3)°, unit-cell volume V = 1309.50 Å3, Z = 2, ρ = 1.179 × 103 kg m−3, and space group P1]. No detectable impurity was observed.