Scale-bearing chrysophytes from tropical Northeast India

This is the first publication describing scale-bearing Chrysophyceae from India by means of electron microscopy. Twenty seven such taxa are described from samples for ponds, rivers and thermal springs. Twenty of these are Mallomonas spp.: M. akrokomos, M. bronchartiana, M. caudata, M. ceylanica, M. costata, M. crassisquanta, M. cyathellata var. cyathellata, M. cyathellata var. chilensis, M. cyathellata var. kenyana, M. guttata, M. heterospina, M. mangofera f. mangofera, M. mangofera f. foveata, M. mangoferea I. reticulata, M. matvienkoae I. matvienkoae, M. mat-vienkoae var. grandis, M. morrisonensis, M. peronoides, M. portae-ferreae , and M. tasmanica . Three are Synura taxa: S. curtispina, S. petersenii f. petersenii , and S. petersenii I. kufferathii . Two are Spiniferomonas species: S. coronacircumspina and S. enigmata. Paraphysomonas and Chrysosphaerella were each represented by one species: P. vestita and C. longispina . The water bodies from which these samples were taken were mostly eutrophic and nutrient rich. The majority of the taxa were obtained during the summer months when water temperatures were high. This contradicts the widely held belief that silica-scaled chrysophytes are mainly found in cold oligotrophic and mesotrophic waters. Mallomonas portae-ferreae and one unidentified species of Mallomonas were recorded also from thermal springs having water temperatures up to 50°C.     

Studies on chrysophyceae from some ponds and lakes in Alaska vi occurrence of synura species

Summary The Synura species found in samples from a variety of freshwater habitats in Alaska are identified by electron microscope studies of their scales. Synura petersenii f. macracantha Petersen & Hansen and Synura spinosa f. curtispina Petersen & Hansen are raised to specific rank. Synura petersenii f. praefracta n. f., Synura curtispina f. reticulata n. f., and Synura echinulata f. leptorrhabda n. f. are described. Electron micrographs of some scales belonging to undesignated formae are given.Some remarks on the ecology of the Synura species are given.

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Zusammenfassung Synura Arten, die in Proben aus verschiedenen Süßwasser-Lokali-täten in Alaska gefunden werden sind, werden durch elektronenmikroskopische Untersuchungen ihrer Schuppen beschrieben. Zwei Formen, Synura petersenii f. macracantha Petersen & Hansen und Synura petersenii f. curtispina Petersen & Hansen, werden zur Rangstufe der Arten erhoben. Zwei neue Formen, Synura petersenii f. praefracta and Synura curtispina f. reticulata, werden beschrieben.Elektronen-mikroscopische Abbildungen einiger Schuppen, die von unbeschriebenen Formen herrühren, werden gegeben.Einige Anmerkungen über die Ökologie der Synura-Arten werden gemacht.

     

Observations on Some Chrysomonads from Scotland

SYNOPSIS. The taxonomy of the genera Mallomonas, Mallomonopsis and Synura is based on their silica scales. Examination of water samples from Southern Scotland in the electron microscope revealed that they were plentiful in the area and permitted detailed observations on new species. Comparative studies are made on the flagella of three known species of Synura ; the "flimmergeissel" of these biflagellates appear to be more or less similar, but the whip-lash flagella show specific differences suggesting a possible secondary taxonomic criterion. The distribution of the three genera is discussed with particular reference to species found in Iceland, Scotland and Japan. A stage in the conjugation of a species of Mallomonas is described.     

Dicoma hindana (Asteraceae), a new species from Somalia

Ortíz, S. & Oubiña, J.R. 1995. Dicoma hindana (Asteraceae), a new species from Somalia. - Nord. J. Bot. 15: 187–189. Copenhagen. ISSN 0107–055X.
A new species of the genus Dicoma (sect. Psilocoma ), from Somalia, is described. The characteristics by which it can be distinguished from related species are listed.     

Environmental filtering and taxonomic relatedness underlie the species richness–evenness relationship

We examined the relationship between species richness (S) and evenness (J) within a novel, community assembly framework. We hypothesized that environmental stress leads to filtering (increasing the proportional abundance of tolerant species) and taxonomic dispersion (decreasing the number of species within genera and families). Environmental filtering would cause a decline in S by eliminating some stress-sensitive species and a reduction of J by allowing only tolerant species to maintain large populations. Taxonomic relatedness may influence both S and J by controlling the nature of interspecific interactions—positive under taxonomic dispersion versus negative under taxonomic clustering. Therefore, the S–J relationship may be a product of environmental filtering and taxonomic relatedness. We tested this framework with redundancy analyses and structural equation models using continental stream diatom and fish data. We confirmed that (i) environmental stress, defined by watershed forest cover, slope, and temperature, caused filtering (lower sensitive:tolerant species abundance ratios) and taxonomic dispersion (elevated genus:species richness and family:species richness ratios); (ii) S and J, which declined with filtering and taxonomic dispersion, exhibited a positive relationship; and (iii) the role of filtering on J was pronounced only under stressful conditions, while taxonomic dispersion remained an important predictor of J across stressful and favorable environments.     

Mallomonas fuegiana (Synurophyceae), a new species of silica scaled chrysophytes from Tierra del Fuego, Argentina

Vigna, M. S. & Kristiansen, J. 1995. Mallomonas fuegiana (Synurophyceae), a new species of silica scaled chrysophytes from Tierra del Fuego, Argentina. — Nord. J. Bot. 15: 439–442. Copenhagen. ISSN 0107–055X.
During the research project "Cryptogamic Flora of Tierra del Fuego", a new species of Mallomonas has been found. It is described here as M. fuegiana , and is placed in the section Torquatae , close to Mallomonas schwemmlii and M. dickii .     

Studies in the genus Polycarpaea (Caryophyllaceae) in Ethiopia

Hedberg, O. 1995. Studies in the genus Polycarpaea (Caryophyllaceae) in Ethiopia. -Nord. J. Bot. 15: 513–517. Copenhagen. ISSN 0107–055X.
A case study is presented of a small critical group of Polycarpaea species in Ethiopia, comprising P. eriantha, P. corymbosa and P. linearifolia . Absence of clear discontinuities in individual features between the three species concerned invited the lumping of them, but studies of the integrated variation in several taxonomic features support their taxonomic independence.     

Two new taxa of Pogostemon (Lamiaceae) from India

Kumar, V. S. & Sharma, B. D. 1995. Two new taxa of Pogostemon (Lamiaceae) from India. - Nord. J. Bot. 15: 163–166. Copenhagen. ISSN 0107–055X.
A new species Pogostemon hedgei and a new variety P. speciosus var. filiformis , are described from South India. Both belong to sect. Pogostemon .     

INFERRING TAXONOMIC POSITIONS AND TESTING GENUS LEVEL ASSIGNMENTS IN COCCOID GREEN LICHEN ALGAE: A PHYLOGENETIC ANALYSIS OF 18S RIBOSOMAL RNA SEQUENCES FROM DICTYOCHLOROPSIS RETICULATA AND FROM MEMBERS OF THE GENUS MYRMECIA (CHLOROPHYTA, TREBOUXIOPHYCEAE CL. NOV.)1

Complete nuclear-encoded small-subunit ribosomal RNA (18S rRNA) coding sequences were determined for the coccoid green algae Dictyochloropsis reticulata (Tschermak-Woess) Tschermak-Woess , Myrmecia astigmatica Vinatzer, and M. bisecta Reisigl, to investigate the taxonomic position of Dictyochloropsis Geitler and of the genus Myrmecia Printz. Phylogenies inferred from these data revealed a sister-group relationship between D. reticulata and certain coccoid green algae that lack motile stages (autosporic coccoids) within the order Microthamniales. The monophyletic origin of the Microthamniales, including autosporic coccoids previously classified in the Chlorophyceae, is clearly resolved by the rRNA sequence data. This finding. shows the considerable taxonomic breadth of that order, whose taxonomic position has been unclear so far. A new class, Trebouxiophyceae, is proposed for this group of green algae. Phylogenetic inferences from the rRNA sequences show paraphyly of the genus Myrmecia. The 18S rRNA sequence data suggest that, among taxa that share similar vegetative cell morphologies, the zoospore characters resolve better the actual genus and species boundaries. Within identical zoospore types, the rRNA data allow further resolution of taxonomic relationships. On the basis of the.se findings, I propose that the genus Friedmannia Chantanachat ± Bold be merged into Myrmecia and that only those species be left in the genus Myrmecia that are identical in particular zoospore characters (i.e. those described in detail for M. israeliensis ( Chantanachat ± Bold) comb, nov.), namely M. astigmatica, M. biatorellae (Tschermak-Woess ± Ptesst) Petersen, and M. israeliensis. Myrmecia bisecta has to be excluded from Myrmecia; its taxonomic position within the Trebouxiophyceae is unclear .     

New and reassessed species of Strobilanthes (Acanthaceae) in the flora of China

Several problems in Strobilanthes Blume (Acanthaceae: Ruelliae) are clarified as a result of collaboration between Chinese and western botanists. Examination of pollen has permitted clear delimitation of four morphologically similar species, Strobilanthes szechuanica (Batalin) J. R. I. Wood & Y. F. Deng, S. labordei H. Lév., S. wakasana Wakasugi & Naruhashi and S. wilsonii J. R. I. Wood & Y. F. Deng, the latter described for the first time in this paper, although first collected more than a hundred years ago. A key is provided to help distinguish these species. The globose, echinulate pollen found in several species from China and Japan and assigned to the genus Championella by Bremekamp is shown by SEM photography to be distinct from other pollen hitherto regarded as the same. Three new species, S. abbreviata Y. F. Deng & J. R. I. Wood, S. lihengiae Y. F. Deng & J. R. I. Wood and S. vallicola Y. F. Deng & J. R. I. Wood are described. S. austinii C. B. Clarke ex W. W. Sm. is lectotypified to show that it is conspecific with S. lamiifolia (Nees) T. Anderson, a species demonstrating trans-Himalayan links. New combinations are made for four species as the authors recognize only a single genus, Strobilanthes within the Strobilanthinae as defined by Bremekamp. S. gongshanensis Tsui and S. aenobarba W. W. Sm. are shown to be only varieties of S. inflata T. Anderson. Illustrations are provided for all new species.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 369–390.     

Systematic studies in Tylosema (Leguminosae)

A contribution to the knowledge of Tylosema (Schweinf.) Torre & Hillc. is presented. The main objectives of this revision were: (1) to elucidate the taxonomic position of the specimens collected in south Angola, (2) to provide a review of species boundaries in the genus, especially between T. fassoglense (Schweinf.) Torre & Hillc. and T. esculentum (Burch.) A.Schreib. and (3) to evaluate the contribution of pollen morphology for delimitation of the species in this genus. Numerical analyses were performed based on morphometric data taken from herbarium specimens. Principal component analysis and cluster analysis divided specimens of Tylosema into four major groups, corresponding to three recognized species and a new taxon. A new micromorphometric character (swollen base of hairs) was found that further contributes to the distinction of T. humifusum (Pic.Serm. & Roti Mich.) Brenan from other species. A new species, T. angolense P. Silveira & S. Castro sp. nov. , is described and illustrated. A taxonomic key and distribution map of studied taxa is also provided. The analyses of pollen morphology allowed for the distinction of the taxonomic groups.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 99–115.     

Developments in the taxonomy of silica‐scaled chrysophytes – from morphological and ultrastructural to molecular approaches

Taxonomy in silica‐scaled chrysophytes has gone through three morphological phases. From primary studies of the cell morphology in the 18th century, the focus was in the 20th century replaced by studies of the silica structures of the cell envelope. Now, in the latest decades the importance of DNA sequencing has been recognized, not only to support the taxonomic framework but also to obtain new understanding of taxonomic relations among particular taxa. In the first part of this review, we provide a historical overview of the developments in the taxonomy of scale‐bearing chrysophytes. In the second part, we present a phylogenetic reconstruction of chrysophyte algae, updated by newly obtained SSU rDNA and rbcL sequences of several isolated Synura, Mallomonas and Chrysosphaerella species. We detected significant incongruence between the phylogenies obtained from the different datasets, with the SSU rDNA phylogram being the most congruent with the morphological data. Significant saturation of the first rbcL codon position could indicate the presence of positive selection in the rbcL dataset. Within the Synurales, the relationships revealed by the phylogenetic analyses highlight the artificial infragenetic classification of Mallomonas and Synura, and the occurrence of cryptic diversity within a number of traditionally defined species. Finally, three new combinations are proposed based on the phylogenetic analyses: Tessellaria lapponica, Synura asmundiae and S. bjoerkii.     

The distribution and variation of Synura species (Chrysophyceae) in Connecticut, USA

The genus Synura was found to be an important member of the phytoplankton communities in many Connecticut lakes, present in more than fifty percent of the 113 collections made during 1984. Thirteen taxa, including a new forma, Synura petersenii f. truttae , were recorded for the first time in Connecticut waters using SEM. S. petersenii was the most important species, present in forty-one percent of the samples. Evidence for denoting S. petersenii var. glabra as a form, instead of a variety, is presented. Ecological preferences for some species are discussed.     

Scale Biogenesis in Synurophycean Protists: Phylogenetic Implications

The Synurophyceae is a class of golden-brown, freshwater, photosynthetic flagellates with a world-wide distribution. A well-developed taxonomy exists where genera and species are distinguished by colony or cell morphology or by the siliceous scales that cover the cells. However, phylogenetic relationships within the class are poorly understood, and incongruous taxonomic concepts occur. This study reviews scale morphology from field-collected samples and controlled culturing experiments as well as from studies of scale biogenesis. The information is used to identify homologous silicification surfaces among taxa and to document the diversity of the resulting scale structures. Thirty-two character states are coded into 11 characters in a cladistic analysis of 13 pivotal taxa. Colonial species are emphasized. One most-parsimonious phylogenetic tree is found (HI = 0, CI = 1). Synura lapponica is shown to be most closely related to Tessellaria volvocina. S. sphagnicola emerges at the base of the tree. Mallomonas caudata and the S. petersenii clade emerge from within Sectio Synura. Chrysodidymus synuroideus appears as an ancestral taxon in the Synura spinosa-like clade (i.e., Series Spinosae). The poorly understood developmental bases for some characters, especially secondary scale structures, are identified and may help focus future research.     

A numerical taxonomic study of lactic acid bacteria from vacuum-packed beef, pork, lamb and bacon

S haw B. G. & H arding C harmaigne D. 1984. A numerical taxonomic study of lactic acid bacteria from vacuum packed beef, pork, lamb and bacon. Journal of Applied Bacteriology 56 , 25–40.
A numerical taxonomic study using 79 unit characters has been performed on 100 isolates of lactic acid bacteria from refrigerated vacuum-packed beef, pork, lamb and bacon. Three clusters were observed at 78% S which contained all the strains apart from three unidentifiable streptobacteria, one Leuconostoc , and one strain of Pediococcus pentosaceus . One cluster (III) consisted of only one strain of Leuc. paramesenteroides and six unidentifiable Leuconostoc strains. The two largest clusters (I and II) were both composed entirely of streptobacteria. Cluster I contained 31 strains (G + C content 33–2–36–9 moles %) which were not identifiable with any described species. Cluster II contained 57 strains (G + C content 40–7–43–7 moles %) which were provisionally identified with Lactobacillus sake or Lact. bavaricus according to the lactic acid isomer produced. The division of nearly all the streptobacteria into two clearly defined clusters has resolved problems which have existed in the classification of lactic acid bacteria from vacuum-packed meat.     

A complex marine shallow-water boring trace: Dendrorete balani n. ichnogen. et ichnospec

Tavernier, A., Campbell. S. E. & Golubic, S. 1992 07 15: A complex marine shallow-water boring trace: Dendrorete balani n. ichnogen. et ichnospec.
Exceptionally well-preserved reticulate boring patterns in Pliocene barnacle shells are described as a new ichnogenus and species. The organism that formed these borings is a presumed phototroph, possibly belonging to green algae. The principles and needs of a taxonomic treatment of microborings as trace fossils in relation to that of their makers are discussed. It is suggested that ichno-taxonomy be extended to include modern traces, when the taxonomic identity of the agent cannot be ascertained. Bio-erosion, endoliths, ichnofossils, marine, microborings, shallow marine, shells .     

Pholidota pygmaea (Orchidaceae) — A new species from Arunachal Pradesh, India

Chowdhery, H.J. & Pal, G.D. 1995. Pholidota pygmaea (Orchidaceae) — A new species from Arunachal Pradesh, India. — Nord. J. Bot. 15: 411–413. Copenhagen. ISSN 0107–055X.
A new species of Pholidota, P. pygmaea from Arunachal Pradesh, India is described.     

Silica-scaled chrysophytes (Synurophyceae) from some rivers and shallow lakes in Hungary

Silica-scaled chrysophytes are a special group in the phytoplankton of rivers and shallow lakes. They are present the whole year at low density, but sometimes — mainly during autumn and spring — some species can become frequent and very numerous to form real water blooms.In this study, seven species of silica-scaled chrysophytes have been recorded and identified by electron microscopy of phytoplankton samples from some rivers and shallow lakes in Hungary. Most of these silica-scaled chrysophytes have previously been found in eutrophic and hypertrophic localities, and almost all of them are common and widely distributed, even cosmopolitan. Only Synura echinulata Korshikov has not previously been recorded from Hungary. Some of them as Synura curtispina (Petersen & Hansen) Asmund, S. petersenii Korshikov, Mallomonas acaroides Perty emend. Ivanov, M. tonsurata Teiling were frequently found in the phytoplankton samples. Sometimes in autumn and winter Synura petersenii was the most abundant species in the phytoplankton and formed blooms.