The invention relates to novel substituted 2-amino-4-alkylamino-1,3,5-triazines of the formula (I) ##STR1## in which R.sup.1 represents in each case optionally substituted alkyl having 2 to 6 carbon atoms or cycloalkyl having 3 to 6 carbon atoms, R.sup.2 represents hydrogen or represents alkyl having 1 to 4 carbon atoms, A represents oxygen or methylene, Ar represents in each case optionally substituted phenyl, naphthyl or heterocyclyl, and Z represents hydrogen, represents halogen or represents in each case optionally substituted alkyl, alkoxy, alkylcarboxyl, alkoxycarbonyl, alkylthio, alkylsulphinyl, alkylsulphonyl, alkenyl or alkinyl, to processes and to novel intermediates for their preparation and to their use as herbicides.