Nevertheless, when we evaluated the richness recorded in papers from these ecosystems (Table 4), we felt that most of the surveys strongly under sampled the plant diversity in their study sites.While most florist studies (Table 4) reported less than 40 species,our physiological survey sampled 49 species, plus an extra 16 species in the florist list. And the local richness was conservatively estimated to be between 68 and 85 species (Figs. 3 and 4).For terrestrial ecosystems it is recognized that random florist collections are more efficient than physiological plots to find new species in a specific site (Ratter et al., 2003; Walter and Guarnieri, 2006). Here we show a similar pattern for aquatic plant communities, with our florist survey recording 32% more species(16 extra species) than physiological sampling. Furthermore,our approach allowed us to estimate the unexampled local biodiversity. Using the richness estimated by Chan 2 (85 species) we calculated that our sampling recorded 58% of the total richness.Using the richness expected by an extrapolation curve three times larger (210 plots) than the actual sampling effort, we estimated that we sampled 68% of the asymptotic richness (Table 3). Of course the numbers produced by each approach are not exactly the same, because extrapolation and estimation involve some margin of uncertainty.