Poa durifolia and its relationship with the phenetic pattern of Poa section Dioicopoa (Poaceae)

Abstract

Poa ligularis var. stricta Parodi ex Nicora & F.A. Roig, described from southern Mendoza through northern Chubut, is raised to the rank of species based on phenetic and nomenclatural studies, and a new name, Poa durifolia Giussani, Nicora & F.A. Roig, is proposed for this taxon. This species was identified
as an independent taxon within the morphological range of variation of Poa section Dioicopoa E. Desv. of Argentina (Giussani, 1997, 2000). Multivariate analysis of specimens of P. ligularis var. stricta, unidentified specimens, and the whole data matrix with specimens of Poa section Dioicopoa, helped
identify the taxon and clarify its taxonomy. In order to characterize P. ligularis Nees ex Steud. and P. durifolia (= P. ligularis var. stricta), numerical analyses, including statistical tests were performed. Recognition of the taxa as separate species is supported by the results of principal component analysis and significant differences in reproductive and vegetative characters. A key to identify Poa durifolia, and
a map of its geographical distribution are given.