The structure of gardmultine, C45H54N 4O10, isolated from Gardneria multiflora Makino, has been determined by single crystal X-ray analysis. The orthorhombic crystals belong to the space group P212121 with a = 8.625(1), b = 20.791 (2), c = 24.494(3) Å and Z = 4. The phase problem was solved by direct methods making use of the technique of negative quartet frequencies to determine the starting set of MULTAN, and refined to a final R value of 0.053 for 3 238 observed diffractometer data taken with Cu-Kα radiation. Gardmultine is a novel bis-indole alkaloid, comprising gardneramine and chitosenine linked by a spiro-five-membered ring.