LECTOTYPIFICATION OF THE NAMES OF AGARUM TAXA (LAMINARIALES, PHAEOPHYCEAE) DESCRIBED BY A.F. POSTELS AND F.I. RUPRECHT

In this paper, we analyzed the history of the genus Agarum. In Kamchatka, the species included in this genus are currently identified as A. clathratum and A. turneri. Currently existing genotypic systematic data, results of our own molecular-phylogenetic research, comparative analysis of descriptions, drawings and synonyms of Agarum species provided in references published by different authors, as well as investigation of the herbarium specimens from BIN RAS (LE) collected by members of the expedition by F.B. Lutke and M.N. Stanyukovich (1826–1829) revealed that, due to a misunderstanding of the volume and specific characteristics of A. clathratum and A. turneri, their species names are currently being used erroneously. Thus, in accordance with the International Code of the Nomenclature of Algae, Fungi and Plants, it is proposed by us to use the name А. clathratum for algae with a wide flat midrib and large perforations, whereas algae with a narrow convex midrib and small perforations should be indicated as A. pertusum. Our taxonomic changes were based on the investigation of herbarium specimens from the BIN RAS (LE) labeled by F.I. Ruprecht, and also on comparison of rDNA sequences obtained by us and those downloaded from the NBCI database. We also typified А. gmelinii, A. pertusum, А. turneri described by A.F. Postels and F.I. Ruprecht.