Benthic marine flora of the Mediterranean Sea: Rhodophyta - Rhodymeniophycidae II. Halymeniales, Nemastomatales, Peyssonneliales, Plocamiales, Rhodymeniales, Sebdeniales

Abstract

After a brief introduction on the 6 Orders object of this second contribution dealing with Rhodymeniophycidae represented in the Mediterranean Sea (excluding the Black Sea), taxa belonging to those Orders are treated in alphabetical order.
The treatment concerns 131 currently accepted taxa, 126 of which at specific and infraspecific level and 5 at generic level only. Moreover, 132 not accepted taxa (at specific and infraspecific level) as well additional 280 taxa (at specific and infraspecific level) synonyms of both accepted and not accepted taxa are treated too. Of 124 currently accepted taxa at specific and infraspecific level, 96 are traditional components of the Mediterranean macroalgal flora, 12 are non-native or introduced, 16 are taxa excludenda. Accepted taxa belong to 39 genera of which: 31 represented in the Mediterranean Sea, 3 are excludenda, and 5 (of which is cited only the name in the text) with no members in the Mediterranean Sea.
The 132 not accepted taxa consist of: 47 taxa inquirenda (3 of which with an illegitimate name); 32 with illegitimate name (3 of which are also taxa inquirenda); 41 with the invalidly published name (32 of which are nomina nuda); 15 are invalid combinations. 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 nomencla-tural conclusions. Moreover, 3 new combinations, 2 of which of taxa not present in the Mediterranean Sea, are also proposed. A glossary of 173 entries, an index of all names of taxa quoted in the text and an errata corrige to the previous paper on Rhodymeniophycidae by Cormaci et al. (2020), complete the paper.