A REAPPRAISAL OF PORPHYRA AND BANGIA (BANGIOPHYCIDAE, RHODOPHYTA) IN THE NORTHEAST ATLANTIC BASED ON THE rbcL–rbcS INTERGENIC SPACER

Sequence data of the rbc L –rbc S noncoding intergenic spacer of the plastid genome for 47 specimens of Porphyra and Bangia from the northeast Atlantic reveal that they fall into 11 distinct sequences: P. purpurea, P. dioica (includes a sample of P. "ochotensis" from Helgoland), P. amplissima (includes P. thulaea and British records of P. "miniata" ), P. linearis, P. umbilicalis, P. "miniata", B. atropurpurea s.l. from Denmark and B. atropurpurea s.l. from Wales, P. drachii, P. leucosticta (includes a British record of P. "miniata var. abyssicola" ), and P. "insolita" (includes P. "yezoensis" from Helgoland). Of these, data obtained for P. purpurea , P. dioica, P. amplissima, P. linearis, P. umbilicalis, P. drachii, and P. leucosticta were based on type specimens or material compared with types. Comparison of sequence data for Porphyra spp. and Bangia atropurpurea s.l. (including B. fuscopurpurea, the type species of Bangia ) confirms that the species are congeneric. The data also confirm that the number of layers that make up the Porphyra thallus are not taxonomically significant. Comparison of sequence data for species from the northeast Atlantic with those for material of two species from the Pacific reveals that the species fall into two distinct groupings: an Atlantic group, containing P. purpurea, P. dioica, P. amplissima, P. linearis, P. umbilicalis, P. "miniata", and B. atropurpurea, and a Pacific group, containing P. "pseudolinearis", P. drachii, P. leucosticta, P. "yezoensis" (including a sample of P. "tenera" ), and P. "insolita" (including P. "yezoensis" from Helgoland). The possibility of alien species in the northeast Atlantic is discussed.     

Phylogenetic relationships of the genus Paramecium inferred from small subunit rRNA gene sequences

The genus Paramecium includes species that are well known and very common in freshwater environments. Species of Paramecium are morphologically divided into two distinct groups: the "bursaria" subgroup (foot-shaped) and the "aurelia" subgroup (cigar-shaped). Their placement within the class Oligohymenophorea has been supported by the analysis of the small subunit rRNA gene sequence of P. tetraurelia. To confirm the stability of this placement and to resolve relationships within the genus, small subunit rRNA gene sequences of P. bursaria, P. calkinsi, P. duboscqui, P. jenningsi, P. nephridiatum, P. primaurelia, and P. polycaryum were determined and aligned. Trees constructed using distance-matrix, maximum-likelihood, and maximum-parsimony methods all depicted the genus as a monophyletic group, clustering with the other oligohymenophorean taxa. Within the Paramecium clade, P. bursaria branches basal to the other species, although the remaining species of the morphologically defined "bursaria" subgroup do not group with P. bursaria, nor do they form a monophyletic subgroup. However, the species of the "aurelia" subgroup are closely related and strongly supported as a monophyletic group.     

PORPHYRA REDIVIVA SP. NOV. (RHODOPHYTA): A NEW SPECIES FROM NORTHEAST PACIFIC SALT MARSHES1

A new species, Porphyra rediviva (Bangiales, Rhodophyta), is described from the northeast Pacific based on morphological, cytological, reproductive, ecological, and molecular characters. This species occurs at high intertidal levels in salt marshes along the coasts of Washington, Oregon, and northern California and exhibits a growth optimum at reduced salinity. It is further distinguished by a distinct demarcation between male and female sectors of the gametophytic thalli of epilithic specimens. The species is found most commonly in the drift or trapped in Salicornia beds, but these detached blades never have been found with sporangia or gametangia. Molecular analyses using restriction fragment length polymorphism patterns of polymerase chain reaction–amplified ribosomal DNA (rDNA) show that this salt marsh Porphyra is conspecific throughout its range and is distinct from other Pacific Porphyra species with similar reproductive patterns. Based on molecular data, P. rediviva is related most closely to P. purpurea from the North Atlantic. Fixed rDNA polymorphisms between the two taxa, however, support ecological and cytological evidence that they should be considered different species.     

PHYLOGENETIC RELATIONSHIPS OF GELIDIALES SPECIES IN COSTA RICA

Despite a general paucity of studies on marine algae in Costa Rica, within the red algal order Gelidiales, 9 species are reported from the Caribbean, and 6 species from the Pacific. In this study 5 species from the southeast Caribbean coast and 2 species from the northwest Pacific coast of Costa Rica were collected for DNA sequence and morphological analyses. At the time of this writing, morphological observations of four Caribbean taxa have identified them as Gelidium microdonticum , Pterocladiella capillacea , P. melanoidea , and Gelidiella acerosa. In rbc L sequence analyses, Gelidium microdonticum is resolved within a clade of small Gelidium species predominantly found in the south Atlantic. Two collections representing different forms of Pterocladiella melanoidea sensu Dawson were found to have identical rbc L sequences. These samples were resolved in rbc L trees with a taxon from Texas identified as P. bartlettii and not P. melanoidea from Europe. Comparisons with type material are being made to verify these identifications so that the status of P. melanoidea in the Caribbean may be determined. The unidentified Caribbean taxon is resolved as a distinct species within the Pterocladiella clade as well. Gelidiella acerosa from Caribbean Costa Rica is closely allied with other Caribbean G. acerosa samples in rbc L trees. The two pacific taxa are small intertidal turf species and have not yet been identified. Sequence analyses resolve these taxa within a large clade of Indo-Pacific and Caribbean Gelidium species.     

THE TYPE SPECIES OF CERAMIUM (RHODOPHYTA), CERAMIUM VIRGATUM ROTH: TYPIFICATION AND PHYLOGENY

The type species of Ceramium is Ceramium virgatum Roth (1797, Cat. Bot I: 148, pl. VIII, fig. 1). This has been treated as a probable synonym of Ceramium nodulosum (Lightfoot) Ducluzeau, one of the species formerly confused under the illegitimate name Ceramium rubrum (Hudson) C. Agardh. However, in 1996 Silva showed that C. nodulosum (Lightfoot) Ducluzeau is a later homonym of C. nodulosum de Candolle 1805, and advocated conserving C. rubrum with a neotype. As an alternative to this, we investigated whether the name C. virgatum might be available for this species. The lectotype of C. virgatum is Roth's illustration of a much-branched, fully corticate, Ceramium specimen from Eckwarden, North Sea, which could represent any member of the ' C. rubrum' group. We obtained material resembling Roth's, from the North Sea island of Helgoland, as a potential epitype. Its rbc L sequence was aligned with sequences of all C. rubrum -like species in the British Isles, i.e. C. secundatum , C. botryocarpum , C. pallidum and ' C. nodulosum '. The Helgoland material was clearly conspecific with ' C. nodulosum ' from Ireland (0.08% divergence). We therefore suggest that the name C. virgatum Roth should be employed for this species. Phylogenetic analyses of these sequences aligned with various representatives of the tribe Ceramieae, placed the North Atlantic C. rubrum -like species in two well-supported clades. In one of these, C. virgatum is basal to C. secundatum and C. botryocarpum. The other clade consists of C. pallidum and a partly ecorticate species resembling C. diaphanum.     

ISOLATION AND CHARACTERIZATION OF PHASE-SPECIFIC COMPLEMENTARY DNAs FROM SPOROPHYTES AND GAMETOPHYTES OF PORPHYRA PURPUREA (RHODOPHYTA) USING SUBTRACTED COMPLEMENTARY DNA LIBRARIES1

The red alga Porphyra purpurea (Roth) C. Agardh has a life cycle that alternates between shell-boring, filamentous sporophytes and free-living, foliose gametophytes. The significant morphological differences between these two phases suggest that many genes should be developmentally regulated and expressed in a phase-specific manner. In this study, we prepared and screened subtracted complementary DNA (cDNA) libraries specific for the sporophyte and gametophyte of P. purpurea. This involved the construction of cDNA libraries from each phase, followed by the removal of common clones through subtractive hybridization. Sampling of the subtracted libraries indicated that 8–10% of the recombinant colonies in each library were specific for the appropriate phase. Of 20 putative phase-specific cDNAs selected from each subtracted library, eight unique clones were obtained for the sporophyte and seven for the gametophyte. After confirming their phase-specificities by hybridization to gametophyte and sporophyte messenger RNA, these 15 phase-specific cDNAs were sequenced, and the deduced amino acid sequences were used to search protein databanks. Two proteins encoded by the sporophyte-specific cDNAs and two by the gametophyte-specific cDNAs were identified by their similarity to databank entries.     

Floridoside,L-Isofloridoside,and D-Isofloridoside in the Red Alga Porphyra columbina (Seasonal and Osmotic Effects)

The quantitative heteroside distribution in Porphyra columbina Montagne and Bangia atropurpurea (Roth) C. Agardh (Bangiales, Rhodophyta) has been measured using 13C-nuclear magnetic resonance spectroscopy and gas-liquid chromatography. In P. columbina, floridoside and both D- and L-isofloridoside were recorded, with concentrations of L-isofloridoside exceeding those of floridoside. All three compounds were also measured in B. atropurpurea. Marked changes in the relative amounts of the heterosides were recorded throughout the season. The role of L-isofloridoside in the osmotic acclimation of P. columbina has been demonstrated.     

DNA barcodes effectively identify the morphologically similar Common Opossum (Didelphis marsupialis) and Virginia Opossum (Didelphis virginiana) from areas of sympatry in Mexico

Two morphologically similar species of opossum from the genus Didelphis-Didelphis virginiana and Didelphis marsupialis-cooccur sympatrically in Mexico. High intraspecific variation complicates their morphological discrimination, under both field and museum conditions. This study aims to evaluate the utility and reliability of using DNA barcodes (short standardized genome fragments used for DNA-based identification) to distinguish these two species. Sequences of the cytochrome c oxidase subunit I (Cox1) mitochondrial gene were obtained from 12 D. marsupialis and 29 D. virginiana individuals and were compared using the neighbor-joining (NJ) algorithm with Kimura's two-parameter (K2P) model of nucleotide substitution. Average K2P distances were 1.56% within D. virginiana and 1.65% in D. marsupialis. Interspecific distances between D. virginiana and D. marsupialis varied from 7.8 to 9.3% and their barcode sequences formed distinct non-overlapping clusters on NJ trees. All sympatric specimens of both species were effectively discriminated, confirming the utility of Cox1 barcoding as a tool for taxonomic identification of these morphologically similar taxa.     

Genetic and historical relationships among geothermally adapted Agrostis (bentgrass) of North America and Kamchatka: evidence for a previously unrecognized, thermally adapted taxon

Agrostis species have been known to evolve ecotypes rapidly in response to unusual edaphic conditions. The geographic distribution of Agrostis taxa in Lassen Volcanic National Park (California) and Yellowstone National Park (Wyoming) in the United States and the Valley of the Geysers (Kamchatka Peninsula) in Russia suggests that Agrostis scabra might have independently evolved morphologically similar ecotypes several times. We used RAPDs to show that, contrary to expectation, the thermal populations are not independently evolved, but instead constitute a single taxon that currently has four names. A UPGMA including the four thermal and nine nonthermal Agrostis taxa showed that the thermal cluster divides into geographically distinct subclusters, but that two morphologically distinct thermal taxa do not cluster independently. Even though currently confused with the thermal populations, nonthermal A. scabra is not closely related. An analysis of molecular variance (AMOVA) showed significant differentiation between the thermal populations and the nonthermal species sampled in this study. Splitting a hypothesized thermal operational taxonomic unit (OTU) into its components (geographically separated populations) does not greatly affect the partitioning of variation among OTUs. All thermal populations therefore should be assigned to the same taxon, but its taxonomic rank cannot be determined at this time.     

PHYLOGENETIC RELATIONSHIPS OF THE BROWN ALGAL ORDERS ECTOCARPALES, CHORDARIALES, DICTYOSIPHONALES, AND TILOPTERIDALES (PHAEOPHYCEAE) BASED ON RUBISCO LARGE SUBUNIT AND SPACER SEQUENCES

Phylogenetic relationships among 23 species of morphologically simple brown algae belonging to the Ectocarpales sensu stricto , Chordariales, Dictyosiphonales, and Tilopteridales sensu stricto , Phaeophyceae (Fucophyceae), were analyzed using chloroplast-encoded RUBISCO large subunit gene sequences ( rbc L) and the associated RUBISCO spacer sequences. Comparison of the observed and expected sequence divergence at the three codon positions of rbc L showed that the level of mutational saturation within the brown algae is minor. Thus, rbc L is well suited for phylogenetic studies in this group. Unweighted parsimony analyses and a neighbor-joining distance analysis were performed using unambiguously aligned rbc L sequences from the above four orders, one marine raphidophyte and two Tribophyceae (Xantophyceae). Polyphyly of Tilopteridales sensu lato (i.e. including Dictyosiphonales) is verified; we therefore recommend the use of Tilopteridales in the strict sense. The Ectocarpales, Chordariales, and Dictyosiphonales are paraphyletic with respect to each other, forming a highly interwoven clade. A separate parsimony analysis of the RUBISCO spacer as well as a combined rbc L and spacer analysis supported the close relationship among the latter three orders, adding to the evidence that they should be subsumed into the Ectocarpales sensu lato.     

MONOPHYLY OF THE GENUS CLOSTERIUM AND THE ORDER DESMIDIALES (CHAROPHYCEAE, CHLOROPHYTA) INFERRED FROM NUCLEAR SMALL SUBUNIT rDNA DATA

We newly sequenced the nuclear-encoded small subunit (SSU) rDNA coding region for 21 taxa of the genus Closterium. The new sequences were integrated into an alignment with 13 known sequences of conjugating green algae representing six traditional families (i.e. Zygnemataceae, Mesotaeniaceae, Gonatozygaceae, Peniaceae, Closteriaceae, and Desmidiaceae) and five known charophycean sequences as outgroups. Both maximum likelihood and maximum parsimony analyses supported with high bootstrap values one large clade containing all placoderm desmids (Desmidiales). All the Closterium taxa formed one clade with 100% bootstrap support, indicating their monophyly, but not paraphyly, as suggested earlier. As to the taxa within the genus Closterium , we found two clades of morphologically closely related taxa in both maximum likelihood and maximum parsimony trees. They corresponded to the C. calosporum species complex and the C. moniliferum-ehrenbergii species complex. It is of particular interest that the homothallic entity of C. moniliferum v. moniliferum was distinguished from and ancestral to all other entities of the C. moniliferum-ehrenbergii species complex. Superimposing all 50 charophycean sequences on the higher order SSU rRNA structure model of Closterium , we investigated degrees of nucleotide conservation at a given position in the nucleotide sequence. A characteristic "signature" structure to the genus Closterium was found as an additional helix at the tip of V1 region. In addition, eight base deletions at the tip of helix 10 were found to be characteristic of the C. calosporum species complex, C. gracile , C. incurvum , C. pleurodermatum , and C. pusillum v. maius. These taxa formed one clade with an 82% bootstrap value in maximum parsimony analysis.     

MAJOR DEVELOPMENTAL REGULATORS AND THEIR EXPRESSION IN TWO CLOSELY RELATED SPECIES OF PORPHYRA (RHODOPHYTA)1

Little is known about the genetic and biochemical mechanisms that underlie red algal development, for example, why the group failed to evolve complex parenchyma and tissue differentiation. Here we examined expressed sequence tag (EST) data from two closely related species, Porphyra umbilicalis (L.) J. Agardh and P. purpurea (Roth) C. Agardh, for conserved developmental regulators known from model eukaryotes, and their expression levels in several developmental stages. Genes for most major developmental families were present, including MADS‐box and homeodomain (HD) proteins, SNF2 chromatin‐remodelers, and proteins involved in sRNA biogenesis. Some of these genes displayed altered expression correlating with different life history stages or cell types. Notably, two ESTs encoding HD proteins showed eightfold higher expression in the P. purpurea sporophyte (conchocelis) than in the gametophyte (blade), whereas two MADS domain‐containing paralogs showed significantly different patterns of expression in the conchocelis and blade respectively. These developmental gene families do not appear to have undergone the kinds of dramatic expansions in copy number found in multicellular land plants and animals, which are important for regulating developmental processes in those groups. Analyses of small RNAs did not validate the presence of miRNAs, but homologs of Argonaute were present. In general, it appears that red algae began with a similar molecular toolkit for directing development as did other multicellular eukaryotes, but probably evolved altered roles for many key proteins, as well as novel mechanisms yet to be discovered.     

Flightlessness and phylogeny amongst endemic rails (Aves:Rallidae) of the New Zealand region.

The phylogenetic relationships of a number of flightless and volant rails have been investigated using mtDNA sequence data. The third domain of the small ribosomal subunit (12S) has been sequenced for 22 taxa, and part of the 5'' end of the cytochrome-b gene has been sequenced for 12 taxa. Additional sequences were obtained from outgroup taxa, two species of jacana, sarus crane, spur-winged plover and kagu. Extinct rails were investigated using DNA extracted from subfossil bones, and in cases where fresh material could not be obtained from other extant taxa, feathers and museum skins were used as sources of DNA. Phylogenetic trees produced from these data have topologies that are, in general, consistent with data from DNA-DNA hybridization studies and recent interpretations based on morphology. Gallinula chloropus moorhen) groups basally with Fulica (coots), Amaurornis (= Megacrex) ineptus falls within the Gallirallus/Rallus group, and Gallinula (= Porphyrula) martinica is basal to Porphyrio (swamphens) and should probably be placed in that genus. Subspecies of Porphyrio porphyrio are paraphyletic with respect to Porphyrio mantelli (takahe). The Northern Hemisphere Rallus aquaticus is basal to the south-western Pacific Rallus (or Gallirallus) group. The flightless Rallus philippensis dieffenbachii is close to Rallus modestus and distinct from the volant Rallus philippensis, and is evidently a separate species. Porzana (crakes) appears to be more closely associated with Porphyrio than Rallus. Deep relationships among the rails remain poorly resolved. Rhynochetus jubatus (kagu) is closer to the cranes than the rails in this analysis. Genetic distances between flightless rails and their volant counterparts varied considerably with observed 12S sequence distances, ranging from 0.3% (Porphyrio porphyrio melanotus and P. mantelli mantelli) to 7.6% (Rallus modestus and Rallus philippensis). This may be taken as an indication of the rapidity with which flightlessness can evolve, and of the persistence of flightless taxa. Genetic data supported the notion that flightless taxa were independently derived, sometimes from similar colonizing ancestors. The morphology of flightless rails is apparently frequently dominated by evolutionary parallelism although similarity of external appearance is not an indication of the extent of genetic divergence. In some cases taxa that are genetically close are morphologically distinct from one another (e.g. Rallus (philippensis) dieffenbachii and R. modestus), whilst some morphologically similar taxa are evidently independently derived (e.g. Porphyio mantelli hochstetteri and P.m. mantelli).     

PORPHYRA SUBORBICULATA, PORPHYRA CAROLINENSIS AND PORPHYRA LILLIPUTIANA - THREE NAMES FOR ONE SMALL PORPHYRA

The genus Porphyra is ancient, successful, and morphologically simple. Its members provide a particular challenge to systematists who must decide whether shared features are a result of homoplasy, or reflect recent common ancestry. Three species of diminutive Porphyra with widespread geographic origins share many common morphological features: P suborbiculata Kjellm. has been reported from the west Pacific and Indian Oceans, P. carolinensis Coll et J. Cox from the west Atlantic, and P lilliputiana W. A. Nelson, G. A.Knight et M. W. Hawkes from New Zealand. Comparison of 18S rDNA sequence data from small Porphyra thalli from Mexico, Japan, New Zealand, Australia and Connecticut indicate that these three taxa in fact belong to one cosmopolitan species, which is distributed over three oceans and two hemispheres. Analysis of sequence data from introns present in the 18S rDNA and from the ITS region suggest that this distribution may be linked to human activity, and raises the question of to which geographic locality this entity is truly endemic?     

On the absence of previously reported Japanese and Peruvian species of Prionitis (Halymeniaceae, Rhodophyta) in the northeast Pacific

Partial rbc L sequences of type specimens, historically significant specimens and recently collected comparative specimens are used to demonstrate that Prionitis decipiens (Montagne) J. Agardh (type locality: Paita, Peru), Prionitis angusta (Harvey) Okamura (type locality: Shimoda, Japan, currently known as Grateloupia angusta (Harvey) Kawaguchi et Wang) and Prionitis cornea (Okamura) E. Y. Dawson (type locality: Shizuoka, Japan, currently known as Grateloupia cornea Okamura), all previously reported from the northeast (NE) Pacific (California, USA and Baja California, Mexico), were not, and currently are not, present. Historically significant specimens from the NE Pacific specifically annotated by E. Y. Dawson as belonging to P. cornea or specifically annotated by I. A. Abbott as belonging to P. angusta were sequenced and shown to belong to either Prionitis linearis Kylin (type locality: La Jolla, California, USA) or to Prionitis filiformis Kylin (type locality: San Francisco, California, USA). The lectotype of Gelidium decipiens Montagne (basionym of Prionitis decipiens ) is narrowed to a single specimen illustrated by Montagne, and a lectotype is designated for P. linearis . The utility of partial rbc L sequences (less than 200 base pairs) for determining the identity of specimens is discussed, as is the importance of sequencing type and historically significant specimens.     

淡水刚毛藻目一新组合种及其系统发育分析

作者于2012-2014年先后在湖北省采集到4株刚毛藻目的丝状绿藻。经鉴定,其形态特征和莫拉瓦刚毛藻Cladophora moravica Gardavsk(1986)非常相似;但相较于刚毛藻属各个种的形态,4株藻体更接近黑孢藻科的分类特征。基于SSU和LSU rDNA序列构建的系统发育树显示,4株刚毛藻目的丝状绿藻均属于黑孢藻科拟湖球藻属(Aegagropilopsis)。据此,作者建议将该种名称作为一个新组合处理,即莫拉瓦拟湖球藻Aegagropilopsis moravica(Dvoˇrák)Zhao et Liu com.nov。拟湖球藻属仅含有3个种:莫拉瓦拟湖球藻、硬枝拟湖球藻和棒状拟湖球藻,其形态特征与湖球藻相近且易混淆,故采用核基因组序列分析方法区分二者是非常有效的。     

Unraveling cryptic invasion of a freshwater snail in Chile based on molecular and morphological data

Cryptic species may cause biological invasions to be overlooked leading to underestimation of the potential impacts of invaders on the new ecosystems. Identification of freshwater snails is challenging because of the scarcity of discriminative morphological characters and the limited taxonomic knowledge of some taxa. Here, molecular and morphological analyses were performed to investigate the identity of viable populations of the genus Physa in aquatic ecosystems of different basins in northern and central Chile, including habitats where the native species Physa chilensis and Physa nodulosa have been traditionally recognized. Molecular analyses based on mitochondrial DNA sequences from the small subunit 16S rDNA and cytochrome c oxidase subunit 1 identified all specimens sequenced as belonging to the globally invasive species Physa acuta. Microscopic examination of the radula and morphological observations of the reproductive system were congruent with these findings. Highly divergent haplotypes found in El Salto suggest multiple introductions of different lineages of the invader in this locality. It is clear that for future management planning a more reliable assessment of the status of P. chilensis and P. nodulosa is required.     

Using DNA barcodes for assessing diversity in the?family Hybotidae (Diptera,Empidoidea)

Empidoidea is one of the largest extant lineages of flies, but phylogenetic relationships among species of this group are poorly investigated and global diversity remains scarcely assessed. In this context, one of the most enigmatic empidoid families is Hybotidae. Within the framework of a pilot study, we barcoded 339 specimens of Old World hybotids belonging to 164 species and 22 genera (plus two Empis as outgroups) and attempted to evaluate whether patterns of intra- and interspecific divergences match the current taxonomy. We used a large sampling of diverse Hybotidae. The material came from the Palaearctic (Belgium, France, Portugal and Russian Caucasus), the Afrotropic (Democratic Republic of the Congo) and the Oriental realms (Singapore and Thailand). Thereby, we optimized lab protocols for barcoding hybotids. Although DNA barcodes generally well distinguished recognized taxa, the study also revealed a number of unexpected phenomena: e.g., undescribed taxa found within morphologically very similar or identical specimens, especially when geographic distance was large; some morphologically distinct species showed no genetic divergence; or different pattern of intraspecific divergence between populations or closely related species. Using COI sequences and simple Neighbour-Joining tree reconstructions, the monophyly of many species- and genus-level taxa was well supported, but more inclusive taxonomical levels did not receive significant bootstrap support. We conclude that in hybotids DNA barcoding might be well used to identify species, when two main constraints are considered. First, incomplete barcoding libraries hinder efficient (correct) identification. Therefore, extra efforts are needed to increase the representation of hybotids in these databases. Second, the spatial scale of sampling has to be taken into account, and especially for widespread species or species complexes with unclear taxonomy, an integrative approach has to be used to clarify species boundaries and identities.     

Caloglossa intermedia, sp. nov. (Rhodophyta) from the western atlantic coast: molecular and morphological analyses with special reference to C. leprieurii and C. monosticha

Caloglossa intermedia , sp. nov. is described from estuaries and salt marshes of Atlantic North America. This species is related to C. leprieurii (Montagne) G. Martens based on the position of rhizoids, whereas it is more similar to C. monosticha Kamiya in the number of cell rows at the nodes. Rhizoidal development of this alga also shows an intermediate characteristic between C. leprieurii and C. monosticha. Crosses were successful between the strains of C. intermedia from Georgia and South Carolina, but neither strain was interfertile with morphologically related species. C. intermedia from Georgia, New Jersey, and South Carolina had identical DNA sequences in the Rubisco spacer and flanking regions of rbc L and rbc S. This alga was more closely related to C. leprieurii in a molecular phylogenetic analysis. The evolution of each morphological character is discussed.