We describe a new species, Calea repanda, from Brazil and discuss novel morphological characters for the taxonomy of this genus. This new species is morphologically similar to C. gentianoides and C. diamantinensis but is distinct due to repand (vs. entire) leaf margins, radiate (vs. discoid) capitulum, larger involucre 12.2–12.7 × 10.6–12 mm (vs. 5.5–9.4 × 2.7–5.2 mm), disc florets 30–40 (vs. 3–9), and fewer pappus scales 7–10 (vs. 15–20). Calea repanda is endemic to the Diamantina plateau in Minas Gerais state, Southeastern Brazil. We provide a map with the geographic occurrence of this species, an illustration with diagnostic characters, and the first taxonomic key for species of C. sect. Calea from Brazil. Furthermore, we propose a more detailed terminology to describe the proportion of the number of paleae and disc florets in the capitulum receptacle.