A new species of the genus Senecio (Asteraceae, Senecioneae) belonging to S. ser. Suffruticosi subser. Caespitosi is described from the pumices of the Ticsani Volcano, central-eastern part of the Moquegua Department in southern Peru. The new species differs from S. moqueguensis by its longer indumentum, different leaf shape and size, wider involucres, narrower calycular bracts, a greater number of phyllaries per capitula, and shorter pappus. A table with the morphological comparison with other species of Senecio is provided and the conservation status of the new species is assessed.