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

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