The county of São José do Rio Preto, State of São Paulo, Brazil, whose climatic and pedological characteristics are referred in this paper, has a reduced and fragmentary area of natural forests, which is mostly occupied by somewhat savanized and, in less grade, ruderalized formations. From the second half of 1962 to the end of 1963, the authors have found species belonging to five different phytogeographic elements, as follow: the General Element, the Amazonic Element, the Atlantic Element, the Meridional Element, and the Central Element. Though no secure] statement can one make on the climax-formation of the region, we may admit that it might be the semideciduous and somewhat xeromorphic latifoliated tropical forest. The problem of origin of the "cerrado" remains an open question yet.