Current knowledge of the hydrophytes of Lake Texcoco, a brackish wetland in central Mexico

The presence of brackish and alkaline environments allows for the settlement of highly adapted flora in and around Lake Texcoco, a relict of the lake ecosystems in central Mexico. The lake's biodiversity, in particular its flora, shows a particular composition. In recent years, the conservation of this Ramsar wetland of international importance has increased, but the knowledge of the aquatic plants and their communities that inhabit this wetland is limited. For this reason, in this research study, we compiled the available literature published from 1957 to 2021 that includes major mentions of hydrophytes records in the lake. A floristic review was generated, with a richness of 97 species, of which 40 are strictly aquatic, 23 semi-aquatic and 34 tolerant. Of these species, 23 are considered halophytes, 46 are freshwater plants and 28 are tolerant to salinity. Some of these species exist only in brackish wetlands; thus, in Mexico’s central basin, they occur only in Lake Texcoco. Also, we found seventy-three native species—eight endemic and one under a national protection category—and sixteen alien species, of which six are invasive. This floristic compilation is proposed as a reference for future works on the diversity and conservation of aquatic plants in this lake remnant to increase the knowledge of a rare and threatened ecosystem in central Mexico.