Two novelties in the genus Senecio L. sect. Senecio of Patagonia (Argentina) are described and illustrated: a new species, S. breviramulus Tortosa & Adr. Bartoli belonging to series Xerosenecio (Cabrera) Cabrera & S. E. Freire, and the new variety pinohachense Tortosa & Adr. Bartoli for S. volckmannii Phil. belonging to series Suffruticosi Cabrera subser. Candidi (Cabrera) Cabrera & S. E. Freire. The new species is allied to S. covasii Cabrera and S. pumilus Tortosa & Adr. Bartoli, from which it differs by the smaller, narrowly elliptic leaves and narrower heads with fewer flowers. The new variety of S. volckmannii differs from the typical variety by the presence of female ray florets and the pedunculate capitula.