Morphological and molecular assessment of <i>Lithophyllum okamurae</i> with the description of <i>L. neo-okamurae sp. nov</i>. (Corallinales, Rhodophyta)

Lithophyllum okamurae has been widely reported in the Pacific Ocean with identification based on morpho-anatomical observations. Two infraspecific taxa, L. f. and angulare, described from Japan, have recorded temperate region of Japan. We assessed branched samples morphologically referable to using data DNA sequences (psbA, rbcL partial LSU rDNA) obtained herbarium specimens, including type material, as well recently field-collected material The molecular analyses showed that these ‘L. okamurae’ contained two species: a cryptic new species which we describe neo-okamurae sp. nov. Because holotype angulare was conspecific original cited protologue okamurae, it is heterotypic synonym okamurae. were similar having warty, lumpy fruticose thalli often forming rhodoliths. can be morpho-anatomically distinguished by thallus tapering or plate-like protuberances (knobby latter) smaller tetrasporangial conceptacle chambers (167–314 µm; 248–380 µm neo-okamurae). Our rDNA sequence (=L. okamurae) identical margaritae, nomenclatural priority over However, considering psbA margaritae could not generated present study, refrain, for moment, proposing taxonomic synonymy between taxa until status its synonyms locality (Gulf California) are clarified.