A revision of the tribe Chondrieae (Ceramiales, Rhodophyta) from the Russian Pacific coast with descriptions of two new species (Chondria pendula sp. nov. and C. epiphytica sp. nov.) and the genus Nothochondria dimorphica gen. et sp. nov

Until recently, two species of the tribe Chondrieae were recorded from the Russian Pacific coast: Chondria dasyphylla and C. decipiens. In this study we re-examined these algae from the region using comparative morphological and molecular analyses. It was shown that both C. dasyphylla and C. decipiens do not occur in the studied region. Specimens previously identified as ‘C. decipiens’ are confirmed as Neochondria ammophila based on molecular and morphological analyses. Specimens from the Russian Pacific coast previously identified as C. ‘dasyphylla’, represent a complex of species, described here as a new genus Nothochondria, with N. dimorphica sp. nov., and two new species, C. epiphytica and C. pendula. Phylogenetic analysis based on COI, rbcL and SSU indicates that N. dimorphica forms a strongly supported clade separate from a diverse clade containing Chondria capillaris, the generitype of Chondria, as well as from the recently described genus, Neochondria. Based on its vegetative anatomy, Nothochondria is intermediate between Chondria and Neochondria. Similarly to Neochondria, it has adventitious cells among pericentral cells, while the distinctness of the axial and pericentral cells throughout the thallus makes it close to Chondria. Data on the distribution of these species along the Russian Pacific coast are provided. There is no evidence that Chondria dasyphylla and C. decipiens that had been reported from the Russian Pacific coast occur here.A new genus Nothochondria and two new species of Chondria, Chondria epiphytica and C. pendula, are proposed.The new taxa are distributed from the southern Sea of Japan to the southern Sea of Okhotsk. There is no evidence that Chondria dasyphylla and C. decipiens that had been reported from the Russian Pacific coast occur here. A new genus Nothochondria and two new species of Chondria, Chondria epiphytica and C. pendula, are proposed. The new taxa are distributed from the southern Sea of Japan to the southern Sea of Okhotsk.