Novelties on the distribution of Colletia spinosissima, Pterocaulon balansae and Saccharum trinii in Tandilia (Buenos Aires) and their possible causes

Abstract

This report provides new data about the geographical distribution of some native species from nothern Argentina as Colletia spinosissima (Rhamnaceae), Pterocaulon balansae (Asteraceae) and Saccharum trinii (Poaceae). Based on the analysis of collection records, bibliographic records and on-line databases, the orographic System of Tandilia (also called “Sierras Septentrionales de Buenos Aires”) is established as the southern limit of their range. We propose some possible causes of the presence of peripheral populations of these three species in this hilly system, such us climate change, anthropogenic factors and methodological absences.