In a mesophyll forest at the State Park of "Morro do Diabo", in the municipality of Teodoro Sampaio, State of São Paulo (22º30'S, 52º20'W) the floristic composition was surveyed. The point centered quarter and quadrant methods were used to survey trees with a diameter equal or greater than 10 cm at breast height. These methods were used as a function of soil features, drainage and physionomical characteristics of the place where the samples were taken. The quarter method sampled 462 points with intervals of 30 m, and the other one had an area of approximately 26.900 m². The phytosociological parameters will be reported in a future paper. The floristic data were important to the resettlement of launistic groups, particulary Leontopithecus chrysopygus Mikan, 1823 ("mico-leão-preto") within remaining areas. The check list also included some species colected in other areas of the Park. There were verified in the sampling areas and surrondings, 113 species, 95 genera and 42 families of trees. Six (6) families contributed with 56% of the total num ber of species. The most representative families in the Park were the following: Leguminosae 25 (13 Faboideae, 6 Caesalpinioideae and 6 Mimosoideae), Rutaceae 11, Meliaceae 8, Lauraceae 7, Euphorbiaceae 7 and Myrtaceae 6. The checklist showed that the State Park of "Morro do Diabo" has a great floristic heterogeneity.
forest; floristic composition; State Park of "Morro do Diabo"