Update of the vascular flora of the Santa Rosa wetland - Chancay (Lima, Peru).
The wetlands of the central coast of Peru have more than 100 species of vascular plants. Of them, Santa Rosa (Chancay, Lima) has one of the highest richness of vascular flora. Considering that the last inventory for this wetland was done almost 10 years ago, the objective of the present study was to update its vascular flora, updating the list and discussing the implications of this changes. As a result of an annual sampling (4 quarterly samples), 57 species of vascular plants have been reported, in 54 genera and 26 families. The families with the richest species were Poaceae (9), Asteraceae (7) and Araceae (5).97% of the species were herbs; 60% have been considered potential invaders; 65% have presented some potential use. Twenty new species have been recorded for this wetland (12 of them, new records for wetlands off the coast of Lima); 30 species of the historical records were not found in this last sampling. Considering these results, the similarity between the coastal wetlands of Lima maintains a low average (Jaccard Index = 0.32) which is an indicator of high complementarity and exchange of species between coastal wetlands. The Santa Rosa wetland remains the wetland of the coast of Lima with more richness and presence of potentially invasive species. The anthropic impact caused by agriculture, livestock and waste disposal, influence the exchange of species in the area. Due to its floristic richness, ecosystem services and goods that it provides, this wetland must be consider like an important ecosystem to conserve.