The biological reserve of the Serra de Paranapiacaba is part of the Serra do Mar at Santo André city, São Paulo state, Brazil (23º4TS, 46º19'W, 800m above sea level). It is covered with a tropical rain forest and is the most rainy place of Brazil. It stands near (16km) of Cubatão city (at sea level) from were receives a great deal of air pollutants. The principal aim of this work is verify the old and recent lichen floras of the reserve. Altogether 63 species were found. The most (16) of the 25 species held at the SP herbarium (Instituto de Botânica de São Paulo) could not be collected in 1988 and nowadays 60% of the lichens are Parmelia s.l. species. No Stictaceae or corticolous fruticose species, wliich are present at the herbarium, could be recollected in 1988. Air pollution, too high umidity and shade can together be the responsible for the flora poorness.
lichens; flora; São Paulo; rain forest