Lycophytes (Equisetopsida: Lycopodiidae) from the Central Hills of Argentina: a panbiogeographic approach

Abstract

Lycophytes are the most ancient lineage of vascular plants and include Lycopodiaceae, Isoëtaceae and Selaginellaceae. They are a monophyletic group separated from ferns and seed plants and are especially useful for establishing biogeographic patterns, due to their lack of coevolutionary relationships with biotic vectors, their monophyly and their remarkable morphological conservatism. The individual tracks of the seven taxa of lycophytes from central Argentina were drawn and the generalized track obtained shows that the central hills of Argentina are the austral extreme of the distribution of a Neotropical biotic component, with closer relationships with the Subandean hills and the Bolivian and Peruvian Andes than to the Chaco (where they are included), bordering the South American Transition Zone. The latter is characterized by arid environments and is a successful barrier for Lycophytes, separating the austral region of Argentina and Chile from the other parts of South America.