The plasticity of functional attributes is an important strategy for the acclimation and establishment of plants in areas that undergo natural regeneration. The irregular rainfall of the Brazilian tropical dry forest is an important environmental filter for the determination of the set of species that can successfully establish in different stages of the regeneration process and influences the plant acclimation responses to the environmental conditions at each stage of ecological succession. In order to test the hypothesis that pioneer plants which can establish themselves, at the same time, in areas at different stages of regeneration have high phenotypic plasticity, we investigated the endemic tree species Poincianella pyramidalis Tull., which can be found in all stages of the regeneration process in the Brazilian tropical dry forest. Three areas were selected at different successional stages (early, intermediate and late), and the functional attributes of water status, gas exchange, leaf nutrients, specific leaf area, leaf construction costs and payback time were assessed. In the three successional stages all individuals had similar age. Measurements were taken in April, for two consecutive years, a dry and a wet. The evaluated parameters in this study showed changes according to successional stage. The highest leaf water potential was found in the late stage in the rainy year and lowest in the dry year. This behavior may be related, in addition to soil water availability, to a stronger competition for resources in these areas. Gas exchange and nutrient use efficiency were higher in 2013 and in the late successional stage, which exhibited higher soil moisture, a lower vapor pressure deficit and higher nutrient mobilization. There were no differences in the construction cost per unit mass between the stages, but differences in specific leaf area led to changes in cost per area. The payback time was shorter in the wettest year. For the driest year, the late stage showed greater energy use efficiency. The results show that the P. pyramidalis’ attributes varies according to the successional stage, showing phenotypic plasticity. However, the strongest differences are observed between years, demonstrating that water is the main factor that coordinates the functional changes that confers its ability to acclimatize.