The Parque Estadual das Fontes do Ipiranga is within the urban area of the São Paulo city (São Paulo state, Brazil) and through the years has received air effluents from a smelter of the vicinity. The aim of this work is to verify the change of the park's lichen flora by comparison of the extant flora with that held at the SP herbarium. Only 9 species can be found nowadays. 7 of them are very rare and from youngless populations. Parmotrema tinctorum (Nyl.) Hale is rare. Pseudoparmelia texana (Tuck.)Hale appears in the collections after 1973 and is now abundant, covering great trunk extensions at exposed places.
lichens; flora; São Paulo; pollution