Laboratory experiments were undertaken to investigate the auto-toxic effects of Anastatica hierochuntica and possible effects on five other desert plants: Rumex cyprius, Trigonella stellata, Diplotaxis harra, Cleome droserifolia, and Farsetia aegyptia. Seed germination, seedling growth, and cell division of all species tested were inhibited by the shoot aqueous extract of A. hierochuntica. A gradual increase in the percentage of prophase and decrease in the other mitotic stages as well as the mitotic index were observed with increasing extract concentration. At an extract concentration of 8 % the mitotic index was reduced from the control by 55% in C. droserifolia, 54% in T. stellata, 45% in F. aegyptia, 43% in A. hierochuntica, and 35% in R. cyprius. The inhibitory substances are apparently released onto soil by repeated washing of the standing plants by rain and dew interception.