Background.

Knowledge on the algal species richness in the state of Yucatán has varied considerably over time; from the works in 1935 by Taylor that recorded 27 species, to works in 2010 that included 285 spp.

Goals.

Update the diversity of macroalgae and cyanoprokaryotes, to integrate the Yucatan Phycological Flora in terms of species richness and distribution by general environments to detect the habitats that have been studied with different intensity.

Methods.

Macroalgae and Cianoprocariontes species records were selected from three sources: publications, herbarium collections, and projects, to generate the database with records at the species or infraspecific level, and data from which and how many habitats they have been found.

Results.

462 species were registered: 194 Rhodophyta, 138 Chlorophyta, 54 Phaeopyceae and 76 Cyanoprokaryota, where 35 are new records not included in previous integrations. Records were considered according to their distribution in the following general environments: reef, coastal, or lagoon. The environment that recorded the highest species richness was the reef with 310 infrageneric taxa; although they mainly come from the Alacranes reef.

Conclusions.

There is a great difference in the number of species mentioned in different studies, this is the result of different methods, intensity, sampling time, sites, or habitats studied. The northern coast of Yucatan is very extensive, and we consider that, although there are many works on benthic macroalgae, some taxa and habitats have been little studied. Such is the case of Cyanoprokaryota and Phaeophyceae, and reef environments.