scholarly journals The species of Mentzelia (Loasaceae) in Mexico, part 1: Sectional diversity

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
John Schenk ◽  
Carolina Granados Mendoza ◽  
Andres Eduardo Estrada-Castillón
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
North America ◽  
Species Distributions ◽  
Distribution Patterns ◽  
Species Boundaries ◽  
Western North America ◽  
Species Complexes ◽  
Scanning Electron ◽  
Study Species

Background: Mentzelia (Loasaceae) is a genus of approximately 95 species that are largely distributed in western North America; however, much ambiguity remains regarding species in Mexico. Questions: What species of Mentzelia occur in Mexico and how can they be distinguished? Study species: Mentzelia Methods: Fieldwork, herbarium studies and scanning electron microscopy were carried out to determine the diversity of Mentzelia species in Mexico. Results: Twenty-five species of Mentzelia occur in Mexico, of which four taxa are endemic to the country. Five of the six sections of Mentzelia occur in Mexico. Mentzelia section Mentzelia was the most species rich in Mexico (8 spp.), followed by section Trachyphytum (7 spp.), section Bartonia (6 spp.), section Bicuspidaria (3 spp.), and section Dendromentzelia (1 sp.). The sections have different distribution patterns, with some restricted to few areas and one widespread across most of Mexico. Conclusions: This study is the first treatment of Mentzelia that encompasses all species and regions of Mexico, which includes approximately 26 % of the worldwide Mentzelia species. In-depth studies of the species in the region are needed to abate gaps in our knowledge on the extent of species distributions and to clarify species boundaries among some problematic species complexes.

scholarly journals The species of Mentzelia (Loasaceae) in Mexico, part 2: Mentzelia section Bartonia

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
John Schenk ◽  
Carolina Granados Mendoza ◽  
Andres Eduardo Estrada-Castillón
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Species Diversity ◽  
North America ◽  
Species Identification ◽  
Seed Coat ◽  
Western North America ◽  
Distribution Ranges ◽  
Scanning Electron ◽  
Study Species

Background: Mentzelia (Loasaceae) is primarily distributed in western North America. The genus is classified into six monophyletic sections, among which species of section Bartonia are particularly poorly understood. Questions: What species of Mentzelia section Bartonia occur in Mexico? What are the species distribution ranges and what are their defining attributes? Study species: Mentzelia section Bartonia. Methods: Field, herbarium, distribution, and scanning electron microscopy studies were conducted to assess species diversity. Seed coat microsculpture patterns were evaluated to confirm species identities and understand their distributions throughout Mexico. Results: Six species from section Bartonia were recognized, with taxa distributed into either the Chihuahuan or Sonoran deserts. Mentzelia longiloba var. pinacatensis is the only Mexican endemic. Conclusions: Although this work comprehensively addressed the species of section Bartonia in Mexico, two groups will continue to present identification challenges: the M. longiloba and M. mexicana-M. saxicola complexes. Overlapping and variable characters will continue to complicate species identification in the M. longiloba complex, while the late-season loss of primary leaves will obscure species identification between M. mexicana and M. saxicola.

Elemental Analysis of Alkalis and Dental Deposits Associated with Coca Chewing in Ecuador

2006 ◽  
Vol 17 (1) ◽  
pp. 77-89 ◽  
Author(s):  
Douglas H. Ubelaker ◽  
Karen E. Stothert
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Spectral Analysis ◽  
North America ◽  
Elemental Analysis ◽  
X Ray ◽  
Tooth Structure ◽  
Elemental Analyses ◽  
The Relationship ◽  
Scanning Electron

AbstractThe relationship between Andean coca use and dental deposits is explored through the use of scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Elemental analyses of samples of large dental deposits from archeologically recovered skeletons from Ecuador dating between 500 B.C. and A.D. 1532 are compared with those of normal calculus deposits of individuals from North America (modern and precontact), of normal tooth structure and of samples of alkali recovered from Ecuadorian artifacts thought to have been employed in coca use. Spectral analysis revealed homogeneity among all dental samples (deposits and structure) and that they are distinct from the elemental pattern revealed in the analysis of the artifact alkalis.

scholarly journals Molecular phylogeny and morphologic data of strains of the genus Coelastrella (Chlorophyta, Scenedesmaceae) from a tropical region in North America (Yucatan Peninsula)

2017 ◽  
Vol 95 (3) ◽  
pp. 527 ◽  
Author(s):  
Katia Ancona-Canché ◽  
Silvia López-Adrián ◽  
Margarita Espinosa-Aguilar ◽  
Gloria Garduño-Solórzano ◽  
Tanit Toledano-Thompson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phenotypic Plasticity ◽  
North America ◽  
Yucatan Peninsula ◽  
Tropical Region ◽  
Its2 Rdna ◽  
Yucatán Peninsula ◽  
Good Support ◽  
Scanning Electron

<p><strong>Background: </strong>Scenedesmaceae family exhibits great morphological variability. High phenotypic plasticity and the presence of cryptic species have resulted in taxonomic re-assignments of Scenedesmaceae members.</p><p><strong>Study strains: </strong><strong>S</strong>trains CORE-1, CORE-2 and CORE-3 were characterized.</p><p><strong>Study site: </strong>Yucatan Peninsula</p><p><strong>Methods: </strong><strong>Morphological analyses were executed by optical and scanning electron microscopy. P</strong>hylogenetic relationships were examined by ITS-2 and ITS1-5.8S-ITS2 rDNA regions.<strong></strong></p><p><strong>Results:</strong> Optical and scanning electron microscopy analyses indicated spherical to ellipsoidal cells and autospore formation correspond to members of the family Scenedesmaceae, as well as observable pyrenoid starch plates. Detailed morphology analysis indicated that CORE-1 had visible granulations dispersed on the cell wall, suggesting identity with <em>Verrucodesmus verrucosus</em>. However CORE-1 did not show genetic relations with this species, and was instead clustered close to the genus <em>Coelastrella</em>. CORE-2 did not show any particular structure or ornamentation, but it did show genetic relations with <em>Coelastrella</em> with good support. CORE-3 showed meridional ribs from end to end, one of them forked and well pronounced, and orange cells in older cultures characteristic of <em>Coelastrella</em> specimens. Phylogenetic trees of ITS-2 and ITS1-5.8S-ITS2 rDNA sequences indicated with good support that all strains were related to the genus <em>Coelastrella</em> despite their morphologic differences.</p><p><strong>Conclusions: </strong>This study reports freshwater <em>Coelastrella</em> strains from a tropical region in North America (Yucatan Peninsula) for the first time. The results contribute to knowledge of <em>Coelastrella</em> species, and the fact that they do not always show structures that are useful for taxonomic assignment, probably as a result of phenotypic plasticity.</p>

scholarly journals The diatom genus Gomphoneis Cleve (Bacillariophyceae) from Lake Baikal, Russia

Phytotaxa ◽  
2013 ◽  
Vol 154 (1) ◽  
pp. 1 ◽  
Author(s):  
JOHN P. KOCIOLEK ◽  
MAXIM S. KULIKOVSKIY ◽  
CÜNEYT N. SOLAK
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lake Baikal ◽  
Western North America ◽  
The West ◽  
Nw China ◽  
The World ◽  
Diatom Genus ◽  
Scanning Electron ◽  
Species Flocks

We describe 22 new species of Gomphoneis, and report several previously described taxa, from historical and recently made collections from Lake Baikal, Russia. We use light microscopy to document all taxa, and scanning electron microscopy to illustrate several of the species from the lake. All of the species present in Lake Baikal are part of the Elegans subgroup of the genus. Despite previous reports, we could find no representatives of the Herculeana subgroup in Baikal. We provide comparisons between the taxa, and document variability in the features found in the species. Two groups within the Elegans subgroup are present; most have 4 (or more) stigmoids, while a minority of the species lack stigmoids. We suggest that the species in Lake Baikal have two origins; one from the West, where an arc of related species spans Mongolia, NW China to Macedonia, and the second from western North America. Radiation of the two groups has resulted in species flocks. The number of Gomphoneis species in Lake Baikal is the largest number of species of the genus anywhere in the world.

Gomphosinica selincuoensis sp. nov., a new diatom (Bacillariophyceae) from North Tibet, China

Phytotaxa ◽  
2019 ◽  
Vol 423 (3) ◽  
pp. 195-205 ◽  
Author(s):  
LI YANG ◽  
QING-MIN YOU ◽  
J. P. KOCIOLEK ◽  
LI-QING WANG ◽  
WEI ZHANG
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
North America ◽  
The Other ◽  
Central Portion ◽  
Similar Species ◽  
A New Species ◽  
Scanning Electron

A new species, Gomphosinica selincuoensis sp. nov., is described from Lake Selincuo, North Tibet, China. This taxon is clearly different from the other species in genus Gomphosinica, with a distinctly protracted, rostrate headpole, relatively higher striae density, and distinctive areolae arrangement within the striae. Striae have areolae mostly in 3 rows, but there are places near the central portion of the valve and at footpole where there are only 2 rows of areolae per stria. Characteristics of this taxon, as observed in light and scanning electron microscopy, support its systematic placement in the genus Gomphosinica. This new species is compared with similar species in Gomphosinica from China and North America, and the biogeographic distribution of the genus is discussed.

Isoetes ×echtuckerii, hyb. nov., a new triploid quillwort from northeastern North America

2000 ◽  
Vol 77 (11) ◽  
pp. 1662-1668 ◽  
Author(s):  
Daniel F Brunton ◽  
Donald M Britton
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Scanning Electron Microscopy ◽  
North America ◽  
United States Of America ◽  
Interspecific Hybrid ◽  
Eastern Canada ◽  
Northeastern North America ◽  
Spore Ornamentation ◽  
Scanning Electron

A new interspecific Isoetes hybrid, I. echinospora Dur. × I. tuckermanii A. Br., is described from northeastern North America by means of cytology and the scanning electron microscopy of spores. Isoetes ×echtuckerii D.F. Brunton and D.M. Britton, hyb. nov., is the name proposed for this taxon. It is triploid, produces only aborted, sterile spores and has spore ornamentation intermediate between that of its putative parents. Populations have been identified in eastern Canada and the adjacent United States of America growing in association with one or both parents in shallow, fresh water along oligotrophic lake and river shores. Key words: Isoetes ×echtuckerii, interspecific hybrid, Canada, United States of America.

scholarly journals AN EXAMINATION OF TARNISHED PLANT BUG FEEDING INJURY ON STRAWBERRY

HortScience ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 259C-259 ◽  
Author(s):  
David T. Handley ◽  
James E. Pollard
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
North America ◽  
Fruit Development ◽  
Tarnished Plant Bug ◽  
Development Stages ◽  
Feeding Sites ◽  
Scanning Electron ◽  
Localized Damage

The tarnished plant bug (Lvgus lineolaris) is a serious pest of strawberries in North America, causing a severe malformation of the receptacle known as “apical seediness” or “buttoning”. Light and scanning electron microscopy were used to assess tarnished plant bug feeding on strawberries and to determine the nature of the injury. During early fruit development stages (anthesis to petal fall) the primary feeding sites were developing achenes. Feeding sites on more developed fruit changed to receptacle tissue, usually close to an achene. The “buttoning” malformation of strawberries associated with tarnished plant bug is most likely a result of the destruction of achenes during early fruit development stages. Feeding on receptacle tissue later in fruit development causes more localized damage, such as creases and indentations.

Description of the larva of Oulimnius echinatus Berthélemy (Coleoptera: Elmidae: Elminae)

Zootaxa ◽  
2009 ◽  
Vol 1984 (1) ◽  
pp. 57-60
Author(s):  
FEDOR ČIAMPOR JR. ◽  
ZUZANA ČIAMPOROVÁ-ZAŤOVIČOVÁ ◽  
JÁN KODADA
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
North America ◽  
North Africa ◽  
Systematic Position ◽  
Mature Larva ◽  
Time Scanning ◽  
First Time ◽  
Scanning Electron

The mature larva of Oulimnius echinatus Berthélemy is described for the first time, based on material from Mallorca (Spain). Morphologically the larva of O. echinatus resembles those of O. jaechi Hernando, Ribera & Aguilera and O. fuscipes (Reiche, 1879), from which it differs in the distinctly denser dorsal granulation, the less prominent setiferous tubercle on posterior angles of tergites and the absence of mesal setiferous tubercle on tergites and ventrites. We used for the first time scanning electron microscopy to describe the morphology of an Oulimnius larva. The genus Oulimnius Gozis occurs in Europe, North Africa and North America (Kodada & Jäch 2005; Jäch et al. 2006). To date, 16 species and subspecies have been described, although the systematic position of the two American species within the genus is open to question.

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