The swamps located at the basins of the Amazonas and Solimões rivers are denominated "várzeas". In these areas, flooding is a natural event that changes the structure and composition of the local plants. Thus, knowing the species diversity in these Amazon region areas is extremely important to understand the dynamics of the natural regeneration of the Amazon ecosystem species. Accordingly, the goal of this study was to survey the soil floristic composition at the bottom of the Manaquiri Lake, Amazon, during an exceptional dry period in 2005. Plants were collected in two areas of the lake in November 2005. Flora sampling was carried out using a 0.36 m² wood frame, randomly cast 20 times at each site studied. The emergent vegetation at both collection sites was of 5,958 individuals distributed in seven families and nine species. The most representative families in number of species were Poaceae and Cyperaceae. Cyperus esculentus and Luziola spruceana were the most frequent, while Mimosa pudica and Alternanthera sessilis presented the highest abundance. C. esculentus and M. pudica had higher number of individuals, density and value of importance. The plant species found in this study maintained their growing and developing capacity even after being submerged for a long period.
Amazonia; dry period; weed
