Revision of species of Aristida (Poaceae, Aristideae) from northwestern Argentina

Abstract

The genus Aristida is represented in northwestern Argentina by section Chaetaria with 23 taxa: 18 species and 5 varieties. Aristida nicorae sp.  nov., A. victoriana sp. nov. and A. asplundii var. pauciflora var. nov. are described and illustrated. Aristida laxa var.  longiramea and A. friesii are two new records for Argentina. Aristida achalensis var.  tucumana, A. adscensionis var. bromoides, A. amplexifolia and A. mandoniana are considered synonyms. Aristida divaricata is excluded from the Argentine flora. This paper includes a key  to recognize all species and varieties that grow in northwestern Argentina, as well as descriptions, synonymy, illustrations, geographical distribution and ecological observations.