Benthic marine flora of the Mediterranean: Rhodophyta - Rhodymeniophycidae I. Acrosymphytales, Bonnemaisoniales, Gelidiales, Gigartinales, Gracilariales

Abstract

After a brief introduction on number of members of Rhodymeniophycidae (Rhodophyta) occurring in the Mediterranean Sea (excluding the Black Sea) and on planning of the number of contribution in which they willll be treated, a table showing the present classification of Rhodophyta and the relative "phylogenetic tree" is given. Following a taxonomic-nomenclatural revision, accepted taxa at specific and infraspecific level of the five orders treated in this contribution are 132 (28 of which are inquirenda), including 25 families and 50 genera. One family and 45 taxa at specific and infraspecific level were considered as taxa excludenda, while 31 taxa at specific and infraspecific level were considered as taxa inquirenda. Moreover, it's pointed out the illegitimacy of names of 47 taxa (3 at level of family, 3 at level of genus and 41 at specific and infraspecific level), the invalidity of names of 29 taxa (1 at level of genus and 28 at specific and infraspecific level) and the invalidity of 9 combinations; finally a new combination is proposed. Of each taxon a brief description, preceded by both iconographic references and references reporting its distribution in the Mediterranean Sea, is given. Moreover, the treatment of most taxa is enriched with illustrations, bilingual notes (Italian and English) supporting either synonymies indicated, or taxonomic choices followed or the reasons for considering the taxon as inquirendum and/or excludendum or nomenclatural conclusions. A glossary of 158 entries, an index of all names of taxa quoted in the text and an errata corrige to paper by Cormaci et al. (2017), complete the paper.