Agrostis lenis (Poaceae: Pooideae: Poeae): rediscovery of a rare and presumably extinct species in São Paulo state, Brazil

The grass Agrostis lenis Roseng., Arrill. & Izag., a presumably extinct species in São Paulo state, was recollected in that state after a gap of 89 years. This species is considered rare and threatened in São Paulo. Notes on its distribution in Southeastern Brazil, images and a short description are given