In order to determine the spatial structure of the diterpene alkaloid dictysine unambiguously, x-ray structural analysis has been performed: diffractometer, CuKα radiation, 1028 reflections, direct method, R factor 0.118. It has been established that dictysine has not a songorine but a denudatine skeleton. All the hydroxy groups participate in inter- and intramolecular hydrogen bonds. © 1983 Plenum Publishing Corporation.