Abstract
Senecio festucoides is described from northern Chile. The new species is morphologically similar to the discoid caespitose Andean species and belongs to the subgroup displaying yellow corollas and yellowish anthers and style branches. It is characterized by a weak, not self-supporting stem, narrowly linear leaves, long pedunculate capitula with (17-)21 involucral bracts, and minutely papillose achenes. Among other characters, the color of the corollas, anthers, and style branches and the number of involucral bracts differentiate it from S. scorzonerifolius, which is the morphologically closest species. The new species thrives in the desertic Puna ecoregion and grows amongst tufts of Festuca chrysophylla (Poaceae). Detailed pictures of living plants are provided, as well as a distribution map and a dichotomous key to the discoid caespitose Senecio species from northern Chile.