Background.

Frederick Michael Liebmann explored Mexico for two years visiting Veracruz, Oaxaca, and Puebla collecting plants, seaweed, and freshwater algae. These samples were entrusted to J. Agardh in Lund for his determination and published in 1847.

Goals.

Recognize Liebmann and J. Agardh for being the pioneers in the study of Mexican algae and update the taxonomic status of these names published in Algae Liebmanniae, with emphasis on the first phycofloristic inventory of Mexico.

Methods.

Global integrative works such as the Index Nominum Algarum (INA) and AlgaeBase were consulted, whose main task has been to collect scattered and unclear information on algal names published to date. The original publications and the criteria of the International Code of algae, fungi and plants were used, citing the articles or recommendations offered to clarify, solve, or support taxonomic opinions.

Results.

Thirty species and one variety, cited by J. Agardh for the entire Liebmann expedition itinerary, which consist of 98 names, were considered new. Eight additional new species from other collections were described. Only twelve of them are names in current use (accepted taxonomic names). Twenty-seven non-Mexican taxonomic or nomenclatural proposals were also included. Liebman’s contributions represent 12% of the total number of taxa recorded for Mexico. The new species described by J. Agardh are 1% of this total. Eight of them are part of the 23% of the endemisms for the Pacific of Mexico.

Conclusions.

The origin and taxonomic significance of some of these proposals by J. Agardh have remained uncertain after 175 years, so it is necessary to carry out studies that delve deeper into these taxa to arrive at a real and updated inventory.