Vascular plants of Punta Ballena: dataset for conservation of an endangered hotspot from Uruguay

Punta Ballena is the coastal southern tip of the Sierra de la Ballena, a shear zone of two tectonic plates, located at the beginning of the oceanic coast of Uruguay. Coastal rocky points are especially relevant because of their high plant richness, moreover their vegetation is endangered mainly due to the high tourist – urbanistic development of the coast. This study aimed to determine the list of vascular plants occurring on Punta Ballena coastal rocky point and identify its vegetation communities. Also, to identify endemic species, threatened and of interest for conservation species; and to analyze the species historically documented for the site. Punta Ballena stands out for its remarkable species richness with 427 species, dominated by Asteraceae (82), Poaceae (82) and Fabaceae (26). Five vegetation types were found in the natural area, which allows the combination of species with different adaptations. The site supports five vulnerable species and one endangered species (IUCN), 33 priority species for conservation, two local endemisms and numerous national (13) and regional (45) endemisms. Regarding historical collections, to date Punta Ballena has suffered a loss of 14% of its species, this is likely a direct consequence of the recent urban development. From these historically documented species, we consider five of them to be locally extinct. Due to these overwhelming results, we consider the site a diversity hotspot on the Uruguayan coast. It becomes urgent to generate conservation plans that allow the maintenance of the flora and vegetation communities that are still preserved in the area.