Mangrove species can be divided into true mangroves and mangrove associates. Scientists studied 33 mangrove species to see if true mangroves are different from mangrove associates. They found that true mangroves have lower specific leaf area and leaf nitrogen concentration, but higher leaf succulence compared to mangrove associates. True mangroves also accumulate more salt (Na and Cl) and have lower K/Na ratios. This shows that true mangroves are better adapted to salty environments, while mangrove associates have some salt tolerance. Based on these differences, the researchers were able to reclassify some controversial species.