The status and distribution of Carex subimpressa (Cyperaceae)

1986 ◽  
Vol 64 (1) ◽  
pp. 227-232 ◽  
Author(s):  
A. A. Reznicek ◽  
P. M. Catling
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Natural Populations ◽  
Field Studies ◽  
Diagnostic Character ◽  
Wide Area ◽  
Hybrid Origin ◽  
The Status ◽  
Specific Rank ◽  
Scanning Electron

Carex subimpressa, originally described as a hybrid of C. hyalinolepsis and C. lanuginosa, has been reported over a wide area and beyond the range of C. hyalinolepis. Consequently it has been accorded specific rank. Various aspects of morphology reflected in scatter diagrams as well as intermediate stomatal structure revealed through scanning electron microscopy and sectioning support the hybrid origin as originally proposed. This is further supported by field studies of natural populations where both putative parents were invariably present. Reports from beyond the range of one or both parents are the result of misidentification. The diagnostic character combination includes sparsely pubescent perigynia 4.2–6.4 mm long, with relatively short beaks, leaves 4.5–11 mm wide, and ligules 1.8–9 mm long.

Morphological and genetic variation in the Senecio pinnatifolius complex: are variants worthy of taxonomic recognition?

2004 ◽  
Vol 17 (1) ◽  
pp. 29 ◽  
Author(s):  
I. J. Radford ◽  
R. D. Cousens ◽  
P. W. Michael
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Genetic Variation ◽  
Genetic Relationships ◽  
Field Studies ◽  
Morphometric Study ◽  
Specific Variation ◽  
Statistical Survey ◽  
Formal Recognition ◽  
Scanning Electron

The current taxonomy of the Senecio pinnatifolius complex (formerly Australian S. lautus) is inadequate in describing intra-specific variation. We present several putative taxa as alternatives to current subspecies, based on variants observed during both herbarium surveys and field studies. We sought to establish whether these taxa were objectively justified in terms of morphology and genetic relationships. This was done in three ways. First, a morphometric study of plants grown under standard conditions was undertaken. Second, isozymes were analysed to establish genetic relationships within the complex. Third, achene morphology was examined by scanning electron microscopy. Variants from central Queensland (BRIGALOW V.) and the deserts of central and Western Australia (DESERT V.) were clearly separated from all other variants based on the number of involucral bracts. This differentiation into two major groups may warrant subspecific recognition. Although variation within each of the proposed subspecies was continuous, separation of variants was possible based on statistical survey. This is consistent with their formal recognition as varieties. Further work is required to determine correct nomenclature of proposed subspecies and varieties, and to fully elucidate variation and provenance in inland forms.

Eucalypt phytoglyphs: The micronanatomical features of the epidermis in relation to taxonomy

1971 ◽  
Vol 19 (2) ◽  
pp. 173 ◽  
Author(s):  
SGM Carr ◽  
L Milkovits ◽  
DJ Carr
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Thin Sections ◽  
Hardening Process ◽  
Leaf Surfaces ◽  
The Status ◽  
Species Specific ◽  
High Degree ◽  
Scanning Electron

The eucalypt leaf contains a store of untapped information of potentially great value taxonomic and evututionary studies. Tie cuticie of certain eucalypts is shown to possess a complex and species-specific ornamentation so distinctive that its features can be regarded as diagnostic. The term "phytoglyph" is coined for the constellation of microanatomical features of the surfaces of leaves, including the microanatomy of the cuticle. Phytoglyphic analysis relates to the combination of three methods, light microscopy of stained cuticles, scanning electron microscopy of leaf surfaces, and light microscopy of thin sections of the cuticular and associated structures. Its use is illustrated by the dissection of the "form species" E. dichromophloia into a number of separate and recognizable entities, some of which were previously accorded the status of species. The plant geographical and other implications of this dissection are dealt with. In particular, E. dichromophloia F. Muell. is to be regarded as a species of very restricted distribution. The microanatomical characters of the cuticle are closely controlled products of the epidermal layers. The fact that specimens which (on other grounds) can be grouped together as a species have identical cuticular microanatomy suggests that the phytoglyph is genetically strongly determined and does not consist of inadvertent, trivial surface features with a high degree of plasticity. This in turn raises the problem of the development of the cuticular microanatomy which cannot be explained on current views of the formation of the cuticle by passive diffusion of precursor substances through the epidermal walls, followed by a hardening process.

scholarly journals Phenotypic plasticity of wall ultrastructure in the green alga Pediastrum s.l. (Chlorophyta, Sphaeropleales)

2016 ◽  
Vol 61 (1) ◽  
pp. 73-88 ◽  
Author(s):  
Joanna Lenarczyk ◽  
Konrad Wołowski
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phenotypic Plasticity ◽  
Green Alga ◽  
Phylogenetic Relationships ◽  
Diagnostic Character ◽  
Sem Micrographs ◽  
Wall Ultrastructure ◽  
Scanning Electron

Abstract This study examined wall ultrastructure variability in the microscopic green alga Pediastrum s.l. Its value as a diagnostic character is discussed. Field and cultured material of 21 taxa were compared using light and scanning electron microscopy. Nine ultrastructural elements occurring on the surface of Pediastrum are documented with LM and SEM micrographs. The highest number of taxa showed reticulate ornamentation composed of a trigonal mesh and granules situated on its corners. The paper considers the use of wall ultrastructure to reconcile traditional and modern taxonomical systems with regard to Pediastrum varieties, and addresses the phylogenetic relationships between strains representing different varieties.

scholarly journals Orobanche alba subsp. alba and subsp. major (Orobanchaceae) in Poland: current distribution, taxonomy, plant communities, hosts, and seed micromorphology

2012 ◽  
Vol 26 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Renata Piwowarczyk
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Central Europe ◽  
Plant Communities ◽  
Current Distribution ◽  
Field Studies ◽  
Distribution Range ◽  
Seed Micromorphology ◽  
Critical Revision ◽  
Scanning Electron

Abstract The paper presents the current distribution of Orobanche alba subsp. major and subsp. alba in Poland, based on a critical revision of herbarium and literature data as well as results of my field studies. Most of their localities are in southeastern Poland: in the Małopolska Upland, Lublin Upland, Roztocze Hills, Polesie, Przemyśl Foothills (Pogórze Przemyskie), and Western Bieszczady Mts. These are the northernmost sites known for the species in Central Europe, so the new data extend its distribution range. Maps of distribution of both the subspecies in Poland and of subsp. major in Central Europe are included. Additionally, their seed micromorphology was compared using scanning electron microscopy (SEM). The taxonomy, biology, and ecology of both the subspecies of O. alba are also discussed.

Revision of Navicula striolata (Grunow) Lange-Bertalot and N. rumaniensis Hustedt with the description of N. friedelhinziae sp. nov.

Phytotaxa ◽  
2015 ◽  
Vol 204 (3) ◽  
pp. 117
Author(s):  
Agata Zofia Wojtal ◽  
Nadja Ognjanova-Rumenova ◽  
Krisztina Buczko ◽  
Janusz Siwek ◽  
Bart Van de Vijver
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Type Material ◽  
Similar Species ◽  
Separate Species ◽  
Modern Material ◽  
Poor Understanding ◽  
The Status ◽  
Study Type ◽  
Scanning Electron

Navicula striolata was originally described as N. digitoradiata var. striolata from modern material collected in Sweden. After examination of a sample collected from Belgium, the variety was transferred to N. reinhardtii as N. reinhardti var. gracilior. From this time a large mix up of these and related taxa was observed in the literature. A similar species, Navicula rumaniensis had also been established in 1934 from Neogene Romanian materials but there has been much confusion regarding the status of these taxa, leading to a poor understanding of their distribution. In this study, type material of Navicula digitoradiata var. striolata, N. reinhardtii var. gracilior and N. rumaniensis are revised using light and scanning electron microscopy in order to clarify their identity and to investigate possible conspecificity. The results indicate that these species are not synonyms. Conspecificity of the modern N. digitoradiata var. striolata and N. reinhardti var. gracilior was confirmed and lectotypes of both varieties have been designated whereas N. rumaniensis proved to be a separate species. In addition, the study of Neogene material from Bulgaria revealed the presence of a new Navicula taxon—N. friedelhinziae. The morphology of these and similar taxa is discussed.

Testing species delimitation with larval morphology: scanning electron microscopy analysis of protonymphon larvae of two closely related sea spiders, Pallenopsis patagonica (Hoek) and Pallenopsis yepayekae Weis

2017 ◽  
Vol 31 (4) ◽  
pp. 363 ◽  
Author(s):  
Jeremy Hübner ◽  
Philipp Wagner ◽  
Tobias Lehmann ◽  
Roland R. Melzer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Imaging Techniques ◽  
Species Group ◽  
Larval Morphology ◽  
Close Relationship ◽  
The Status ◽  
Electron Microscopy Analysis ◽  
Species Specific ◽  
Scanning Electron

We used scanning electron microscopy (SEM) to establish species-specific sets of characters for protonymphon larvae of two representatives of the ‘patagonica’ species group of Pallenopsis, P. patagonica and P. yepayekae. The larvae of both species are ‘typical’ protonymphon larvae sensu Bain (2003). Despite the close relationship of the two species, we observed numerous features that allow for differential diagnosis, e.g. general habitus, the number, arrangement and branching type of setules, the armature of the movable and immovable chelifore fingers, and the shape of the dactylus and setules of appendages II and III. SEM is particularly suitable for visualising these features. Our results further support the idea that protonymphon larvae can be identified to species level when adequate imaging techniques are used, as is also the case for larvae of other arthropods. Moreover, the status of the two studied species of Pallenopsis is fully supported by protonymphon larval morphology.

Susceptibility of Limestone Petrographic Features to Salt Weathering: A Scanning Electron Microscopy Study

2013 ◽  
Vol 19 (5) ◽  
pp. 1231-1240 ◽  
Author(s):  
Carlos Alves ◽  
Carlos Figueiredo ◽  
António Maurício ◽  
Luís Aires-Barros
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mass Loss ◽  
Field Studies ◽  
Test Sample ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Natural Stone ◽  
Salt Weathering ◽  
Scanning Electron

AbstractSalt weathering is a major erosive process affecting porous materials in buildings. There have been attempts to relate erosive mass loss to physical characteristics of materials, but in the case of natural stone it is necessary to consider the effect of petrographic features that are a source of heterogeneity. In this paper, we use scanning electron microscopy before and after salt weathering tests in cubic specimens of three limestone types (two grainstones and a travertine) in an attempt to built conceptual models that relate petrographic features and salt weathering susceptibility (represented by mass loss). In the grainstones, the most relevant feature in controlling salt weathering processes is the interface between micrite aggregates and sparry cement that constitute weakness surfaces and barriers to fluid migration. Given the small size of the heterogeneities in relation to the test sample dimension and their spatial distribution, the macroscopic erosive patterns are globally homogeneously distributed, affecting edges and corners. In the travertine specimens, there are macroheterogeneities related to the presence of detritic-rich portions that cause heterogeneous erosive patterns in the specimens. Petrological modeling helps to understand results of salt weathering tests, supporting field studies for natural stone selection.

Proboscis ornamentation as a diagnostic character for the Anoplodactylus californicus-digitatus complex (Arthropoda: Pycnogonida) with an example from the Anoplodactylus eroticus female

Zootaxa ◽  
2006 ◽  
Vol 1311 (1) ◽  
pp. 51 ◽  
Author(s):  
CLAUDIA P. ARANGO ◽  
AMY MAXMEN
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Species Distribution ◽  
Related Species ◽  
External Morphology ◽  
Diagnostic Character ◽  
First Time ◽  
Pacific Species ◽  
Scanning Electron ◽  
Identification Tool

Females of the Indo-Pacific species Anoplodactylus eroticus (Arthropoda: Pycnogonida: Phoxichilidiidae) are described for the first time. The presence of peculiar ventral outgrowths or protuberances on the female proboscis of A. eroticus and 13 other Anoplodactylus species motivates an evaluation of a californicus-digitatus complex, based on external morphology and species distribution. The anatomy and development of proboscis protuberances is assessed using scanning electron microscopy (SEM), Nomarski optics, and flourescence microscopy. External morphology of A. eroticus is compared to that of apparently related species. An identification key for the 14 species of Anoplodactylus with females bearing a proboscis with ventral protuberances is provided here as an identification tool.

scholarly journals A weighted taxonomic matrix key for species of the rotifer genus Synchaeta (Rotifera, Monogononta, Synchaetidae)

ZooKeys ◽  
2019 ◽  
Vol 871 ◽  
pp. 1-40 ◽  
Author(s):  
Tanja Wilke ◽  
Wilko H. Ahlrichs ◽  
Olaf R. P. Bininda-Emonds
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Identification Key ◽  
Diagnostic Character ◽  
Missing Information ◽  
New Approach ◽  
As Species ◽  
Weighted Matrix ◽  
First Time ◽  
Scanning Electron

A new, weighted matrix identification key for 34 largely undisputed species of Synchaeta was created with the aim of providing comparable, detailed and diagnostic character sets for each species that can be applied to live and/or preserved specimens. As part of this process, 14 species of Synchaeta were intensively re-investigated with respect to their habitus and trophi morphology using binocular, light, and scanning electron microscopy, which, together with behavioural observations, revealed several new discriminating characters. Whenever possible, missing information for any character was added for the remaining species from the literature, with the two recently described species Synchaeta arcifera and Synchaeta squamadigitata being considered for the first time in an identification key. Beyond its completeness, our key has two distinct advantages. First, the characters are supported by detailed illustrations of their respective character states whenever possible to both simplify identification and minimize any uncertainty in the descriptions themselves. Second, the new approach of weighting the characters according to their reliability, robustness and/or ease of determination was employed. This latter approach is especially advantageous for soft-bodied rotifers such as species of Synchaeta, where, for example, several external characters can be influenced by preservation and are therefore less diagnostic or reliable. Although the key is as comprehensive as possible, information for many species remains missing for many characters, thereby highlighting the need for additional comprehensive and detailed species (re-)investigations within Synchaeta.

Antagonism of Paraquat Phytotoxicity in Peanuts (Arachis hypogaea) and Selected Weed Species by Naptalam

Weed Science ◽  
1991 ◽  
Vol 39 (4) ◽  
pp. 634-639 ◽  
Author(s):  
Glenn R. Wehtje ◽  
John W. Wilcut ◽  
Daniel P. Dylewski ◽  
John A. McGuire ◽  
T. Vint Hicks
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Arachis Hypogaea ◽  
Leaf Surface ◽  
Field Studies ◽  
Weed Species ◽  
Absorption Studies ◽  
Scanning Electron

Greenhouse and field studies demonstrated that naptalam reduced paraquat activity by as much as 30% on sicklepod, smallflower morningglory, Florida beggarweed, and peanut Sequential application experiments, i.e. naptalam applied 2 or 24 h prior to an application of paraquat, as well as absorption studies utilizing14C-paraquat, indicated that the antagonism was due largely to reduced paraquat absorption. Scanning electron microscopy revealed that application of naptalam, as well as naptalam applied with paraquat, resulted in amorphous deposits on the leaf surface which may account for the antagonism.

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