Calea sessilifolia (Asteraceae, Neurolaeneae), a New Species from the Diamantina Plateau, Minas Gerais, Brazil

A new species of Calea belonging to the Calea myrtifolia complex is described. Calea sessilifolia stands out by the unusual herbaceous habit 0.1 to 0.25 m tall and sessile leaves compared with the remaining species of the complex. The new species is related to Calea arachnoidea, C. heteropappa, and C. semirii due the polylength pappus scales, but is easily distinguished by its height 0.1-0.25 m tall (vs. 0.3-2 m), sessile leaves (vs. petiolate leaves), acrodromous venation (vs. camptodromous or semicraspedodromous), and capitulescence of solitary capitula or rarely a dichasiform cyme and few-branched (vs. branched dichasiform cyme). The new species is described, its taxonomic affinities are discussed, and its main vegetative and reproductive structures are illustrated. In addition, a key for identification and one map with the geographic distribution of the species of Calea bearing polylength pappus scales from Calea myrtifolia complex are provided.