It was studied in this paper the floristic composition and the phytosociology of lha of riverine forest, placed at Tibagi riversides, in Sapopema County, PR (24º01'S, 50º41'W), 780m above sea level. For such purpose, a 100 X 100m plot was divided in 100 of the 10X10m contiguous subplots, using a DBH greater or equal to 5cm. 1560 specimens were sampled, gathered in 41 families, 82 genera and 125 species. The diversity index (Shannon-Weaner) was H'=4,2. The most important species were: Anaderanthera colubrina, Casearia sylvestris, Lueliea divaricata, Esenbeckia febrífuga e Parapiptadenia rígida. The families vvith most specimens sampled were Fabaceae (214) and Myrtaceae (209), which had the highest number of species (18).
Floristic; Phytosociology; riverine forest; northem of Paraná; Tibagi river