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Two of the four currently recognised species of Phymatolithon in South Africa are P. repandum (type locality: Half Moon Bay, Port Philip Bay, Victoria, Australia) and P. ferox (type locality: Natal, KwaZulu-Natal, South Africa). Partial rbcL sequences of the lectotype of P. repandum and the holotype of P. ferox demonstrate that the former is not present in South Africa and does not belong in Phymatolithon, whereas the latter belongs in Phymatolithon, but that the name has been misapplied in South Africa. The correct name for the species, currently called P. repandum in South Africa, is P. ferox. Partial rbcL and psbA sequences of two of the current heterotypic synonyms of P. ferox, Lithothamnion prolixum and Lithothamnion prolixum f. plicatum, show that they are conspecific and do not belong in Phymatolithon. Lithothamnion prolixum is the basionym for the species currently, but incorrectly, called P. ferox in South Africa. Phymatolithon repandum and L. prolixum belong in an as yet undescribed genus. All heterotypic synonyms of currently recognised names of non-geniculate corallines that were placed in synonymy based on morpho-anatomy should not be accepted until confirmed by DNA sequencing.

One of the earliest described non-geniculate coralline algae from the Arctic is Kjellman’s 1877 Lithophyllum arcticum. It has been classified successively in Lithothamnion and Mesophyllum and curre...

The current identification of crustose coralline algae from North Carolina is based on a few morphoanatomical studies from the last century. We reassessed the type specimens of the two Lithophyllum species historically reported from offshore communities in North Carolina, L. intermedium with a Caribbean Sea type locality and L. subtenellum with an Atlantic southern France type locality, using scanning electron microscopy images and diagnostic rbcL sequences. Neither of the sequences generated from the type specimens matched rbcL sequences from contemporary specimens collected from subtidal North Carolina epibenthic communities. On the basis of analyses of rbcL and other loci (psbA, UPA, and COI), we instead found L. atlanticum, recently described from Brazil, and L. searlesii sp. nov. from Onslow Bay, North Carolina. These sequence data show that L. atlanticum is related to northeast Pacific species, whereas L. searlesii is related to Mediterranean species.

Plastid-encoded rbcL and psbA sequences from branched, Caribbean Sea Lithophyllum specimens indicate that four species are present, not one. Short (263 base pairs) rbcL sequences from an isolectotype of L. kaiseri (Gulf of Suez) and the holotypes of L. congestum, L. daedaleum and L. platyphyllum (Caribbean Sea) show that L. congestum and L. daedaleum are conspecific with L. kaiseri, the last having nomenclatural priority. Lithophyllum platyphyllum, currently considered a synonym of L. congestum, is recognised as a valid species. Lithophyllum stictaeforme, originally described from the Mediterranean Sea, is not conspecific with L. kaiseri (as L. congestum) as previously suggested. Lithophyllum neocongestum sp. nov. and L. pseudoplatyphyllum sp. nov. are proposed. Together with L. platyphyllum, these three branched species are so far endemic to the Caribbean Sea. This is the first report, documented by DNA sequence data, of a coralline species (L. kaiseri) widespread through the tropical Indo-West Pacific Oceans, Red Sea and Caribbean Sea.

Nothogenia fastigiata has been reported to exhibit great morphological variability and has been considered to be widely distributed in the Southern Hemisphere. To test its current circumscription, sequences from type material of N. fastigiata and other species currently synonymized with it were compared to those from recent collections of this and other species in the genus. Eight distinct species previously subsumed under the name N. fastigiata were identified. Multiple specimens from southern Chile and a single specimen from Campbell Island (subantarctic New Zealand) were conspecific with type material of N. fastigiata from the Falkland Islands. For other species, molecular analyses of recent collections using the nuclear ITS1-5.8S-ITS2 region of the ribosomal cistron, the chloroplast rbcL and psbA genes and the mitochondrial COI gene indicated a strong geographic pattern to species relationships. Other specimens identified as N. fastigiata from Chile represented up to five species, including N. chilensis and N. fragilis, based on sequences of type material; these Chilean species occurred on a monophyletic branch. We also recognized N. lingula comb. nov. from Tasmania, which is closely related to N. fastigiata, based on sequences of type material. Specimens from mainland New Zealand identified as N. fastigiata fell into a distinct clade with New Zealand N. pulvinata and represented a previously undescribed species, described here as N. neilliae sp. nov. Another New Zealand species, N. pseudosaccata, was distantly related to N. variolosa from Auckland Island and other subantarctic islands south of New Zealand. The New Zealand species were more closely related to South African N. erinacea and N. ovalis than to species of Nothogenia from Chile, including N. fastigiata, although bootstrap support for this interpretation was weak. These genetic data demonstrate that matching DNA sequences from archival Nothogenia material to modern specimens can be used to identify and define new and old cryptic species.

Lindstrom S.C., Hughey J.R. and Martone P.T. 2011. New, resurrected and redefined species of Mastocarpus (Phyllophoraceae, Rhodophyta). Phycologia 50: 661–683. DOI: 10.2216/10-38.1 Recent molecular phylogenetic investigations of the red algal genus Mastocarpus from the northeast Pacific resolved numerous cryptic species. Although species were clearly defined through genetic analyses, the correct names to apply to the species remained unclear due to both morphological variability within species and morphological similarity between species. To determine the appropriate name for each entity, we analyzed DNA from type material of taxa previously ascribed to Mastocarpus. In combination with this analysis, an updated phylogeny based on a broad range of geographical and morphological collections is presented that includes data from nuclear (ribosomal internal transcribed spacers [ITS]), chloroplast (rbcL) and mitochondrial [cytochrome oxidase I (COI)] genomes. By analyzing partial ITS region sequences of type sp...

Hughey J.R. and Hommmersand M.H. 2010. A molecular study of Mazzaella (Gigartineaceae, Rhodophyta) and morphological investigation of the splendens clade from Pacific North America. Phycologia 49: 113–135. DOI: 10.2216/08-68.1 The delineation of species of Mazzaella remains problematic because of similarities in thallus shape and color. To better define species boundaries, molecular phylogenetic analyses and developmental studies of Mazzaella were performed on one of the more taxonomically challenging clades, the splendens group (Mazzaella flaccida, Mazzaella linearis, Mazzaella sanguinea and Mazzaella splendens). Using an expanded rbcL data set, internal transcribed spacer sequences, and a combined analysis, six clades were identified: splendens, californica, rosea, cobinae, oregona, and South American/African. Morphological examination of members of the splendens clade identified differences in their cystocarpic and tetrasporangial development and supported the recognition of two subspecies, M....

Species boundaries in the Gigartinaceae are poorly defined due to the high degree of phenotypic plasticity exhibited by the thallus, with the result that many superfluous taxa have been described. To clarify the taxonomy of species of Chondracanthus Kutzing reported from the Gulf of California and Pacific coast of North America, morphological and molecular phylogenetic studies were performed. Phylogenetic analyses of chloroplast and nuclear DNA yielded nearly congruent hypotheses. DNA from type material was examined from select species to validate the correspondence between modern and historically important collections. Monographic observations on species from Pacific North America were included to clarify species boundaries. Analyses identified two species from the Gulf of California and nine from the Pacific coast. The following statements are supported: (1) Gigartina serrata Gardner is independent of Chondracanthus canaliculatus (Harvey) Guiry, and Chondracanthus serratus (Gardner) comb. nov. ...