Arrival of Senecio angulatus (Asteraceae) in Algeria. — In this contribution, the authors report for the first time the presence of Senecio angulatus L. (Asteraceae) in Algeria. Field observations have shown the presence of this taxon in five localities in the center of the country. The identification was checked with particular regard to closely related taxa (e.g. Senecio mikanioides Harv.).This report indicates a recent arrival of this taxon in Algeria. The ecological and economic consequences of this finding are mentioned while a careful oversight of the spread of this invasive plant in the country is needed