From the leaves of Arundo donax L. a new alkaloid, C12H 13O2N·NMe, has been isolated besides gramine (3-dimethylaminomethylindole). There are indications of the presence of a third alkaloid with phenolic properties. Gramine reacting with methyl iodide in an alkaline medium undergoes a peculiar degradation, a quantitative yield of tetramethylammonium iodide and a substance C9H8N· OMe being obtained. The formation of a normal ethiodide takes place in the reaction of gramine with ethyl iodide in neutral solution, whereas tetramethylammonium iodide and trimethylamine are produced when methyl iodide is used.