Toxicité - jugloneWalnut ToxicityMost members of the Walnut family (Juglandaceae) produce a chemical called "juglone" (5 hydroxy-alphanapthoquinone) which occurs naturally in all parts of these plants. Black walnut, pecan, hickory and others members of the family including Carya, Engelhardtia, Juglans, Platycarya and Pterocarya can produce juglone.www.omafra.gov.on.caLandscaping and Gardening Around Walnuts and Other Juglone Producing PlantsThe greatest concentration of juglone and hydroxyjuglone (a nontoxic, colorless precursor that is converted into the toxic form juglone by sensitive plants and through oxidation) is found in the vegetative buds, leaves, stems, nut hulls, and roots of the plants.extension.psu.edu
