Aquatic Flora of Lake Texcoco, Mexico: Diversity, Endemism, Exotic Species, and Conservation Perspectives

Lake Texcoco, located in the State of Mexico, is one of the most distinctive wetlands in the Basin of Mexico due to its brackish, alkaline sediments, which support a highly specialized aquatic flora uniquely adapted to these conditions. Despite its ecological relevance and historical importance, studies on its plant diversity remain scarce and fragmented. To provide an updated perspective, we conducted a taxonomically curated review of the literature published between 1957 and 2022, compiling a comprehensive checklist of aquatic species for this wetland. The survey revealed a richness of 97 species: 40 obligate aquatics, 24 subaquatics, and 33 tolerant taxa. Within this flora, 24 are halophytes, 46 are freshwater species, and 28 are salinity-tolerant; notably, 81 species are native to Mexico (including eight endemics), while 16 are introduced, six of which are recognized as invasive. These results highlight both the ecological richness and the system's vulnerability to environmental change. The absence of a complete hydrophyte inventory underscores the urgent need for further research, particularly on the physiology of halophytes, the restoration potential of native taxa in degraded habitats, and the ecological interactions shaping aquatic communities. Recognizing Lake Texcoco as an ecological refuge emphasizes not only its conservation value but also its role as a natural laboratory for understanding aquatic biodiversity and as a guide for future restoration strategies in central Mexico.