Weeds are a significant handicap for agriculture on Reunion Island. Control efforts depend on the exact species involved but it is not easy to identify weeds. Conventional flora or manuals are too technical or imprecise or they are not comprehensive enough to identify young plants or incomplete samples. A computer-assisted identification tool now exists, i.e. the software program AdvenRun V.1.0., that makes it easy to recognize the major weeds on Reunion Island. It has a graphics-based identification system that starts of from a composite drawing. The user is free to choose the features described. The species are listed by order of similarity and a complete description is given for each species, including a large number of coloured illustrations and a botanical drawing.