Isoetes × marensis, a new interspecific hybrid from western Canada

1995 ◽  
Vol 73 (9) ◽  
pp. 1345-1353 ◽  
Author(s):  
Donald M. Britton ◽  
Daniel F. Brunton
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
Key Words ◽  
North American ◽  
Interspecific Hybrid ◽  
Western Canada ◽  
Hybrid Plants ◽  
Surface Ornamentation ◽  
Scanning Electron

A new interspecific hybrid in Isoetes, I. maritima Underw. × I. howellii Engelm., is delineated and described from the Shuswap Highlands region of British Columbia by means of cytology and scanning electron microscopy of spores. Isoetes × marensis D.M. Britton and D.F. Brunton, hyb.nov. is the name proposed for this taxon. It is triploid (3x; 2n = 33) and is believed to produce only sterile and (or) aborted spores. Hybrid plants have polymorphic spores that demonstrate size and surface ornamentation features intermediate between those of the putative parents. Three populations were examined, each growing with both of the putative parents in silt and sand among granite cobble over clay along an emergent lakeshore. Isoetes × marensis is the first described North American hybrid involving an amphibious Isoetes. It is expected to be a rare taxon owing to the restricted sympatric area of the putative parents and their tendency to occupy different habitats. Key words: Isoetes, Isoetes howellii, Isoetes maritima, hybrid, British Columbia.

Limited taxonomic value of palea intercostal characteristics in North American Festuca (Poaceae)

1993 ◽  
Vol 71 (12) ◽  
pp. 1651-1659 ◽  
Author(s):  
L. L. Consaul ◽  
S. G. Aiken
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
North America ◽  
Key Words ◽  
North American ◽  
Apical Region ◽  
Key To Species ◽  
Species Groups ◽  
Epidermal Features ◽  
Scanning Electron

Morphology of the intercostal palea region of 34 Festuca species found in North America was investigated using scanning electron microscopy. Palea epidermal features are most diverse in the palea apical region and fully developed in florets approaching anthesis. The intercostal region has long cells 3–15 times longer than wide, with walls that vary from slightly to prominently thickened, and from almost straight to strongly undulate. This variation was observed among paleas collected from different locations and sometimes even on a single palea. The distribution of short cells, almost square in outline, among the long cells varied with species from solitary to paired and from abundant to sparse. Four forms of trichomes were recorded: papillae, hook trichomes, prickle hairs, and macrohairs, with one form usually predominating per species. Silicon was detected in some short cells and commonly in the tips of trichomes. A key to species groups is presented. Key words: scanning electron microscopy, palea, trichomes, silicon, epidermal features, Festuca.

scholarly journals A reexamination of Yuknessia from the Cambrian of British Columbia and Utah

2015 ◽  
Vol 89 (1) ◽  
pp. 82-95 ◽  
Author(s):  
Steven T. LoDuca ◽  
Jean-Bernard Caron ◽  
James D. Schiffbauer ◽  
Shuhai Xiao ◽  
Anthony Kramer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
National Park ◽  
Red Alga ◽  
Fine Scale ◽  
Burgess Shale ◽  
Phylogenetic Affinity ◽  
New Material ◽  
Scanning Electron

AbstractTo investigate the phylogenetic affinity of Yuknessia simplex Walcott, 1919, scanning electron microscopy was applied to the Burgess Shale (Cambrian Series 3, Stage 5) type material and to new material from the Trilobite Beds (Yoho National Park) and specimens from the Cambrian of Utah. On the basis of fine-scale details observed using this approach, including banding structure interpreted as fusellae, Yuknessia Walcott, 1919 is transferred from the algae, where it resided for nearly a century, to the extant taxon Pterobranchia (Phylum Hemichordata). Considered as such, Yuknessia specimens from the Trilobite Beds and Spence Formation (Utah) are amongst the oldest known colonial pterobranchs. Two morphs regarded herein as two different species are recognized from the Trilobite Beds based on tubarium morphology. Yuknessia simplex has slender erect tubes whereas Yuknessia stephenensis n. sp., which is also known in Utah, has more robust erect tubes. The two paratypes of Y. simplex designated by Walcott (1919) are formally removed from Yuknessia and are reinterpreted respectively as an indeterminate alga and Dalyia racemata Walcott, 1919, a putative red alga.

scholarly journals Taxonomic synthesis of the eastern North American millipede genus Pseudopolydesmus (Diplopoda: Polydesmida: Polydesmidae), utilizing high-detail ultraviolet fluorescence imaging

2019 ◽  
Vol 187 (1) ◽  
pp. 117-142 ◽  
Author(s):  
Petra Sierwald ◽  
Derek A Hennen ◽  
Xavier J Zahnle ◽  
Stephanie Ware ◽  
Paul E Marek
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fluorescence Imaging ◽  
North American ◽  
Type Material ◽  
High Quality ◽  
Subjective Synonym ◽  
Scanning Electron

Abstract The species of the eastern North American millipede genus Pseudopolydesmus are reviewed. Synonyms and comprehensive literature citations are provided for each of the eight recognized species. Diagnostic morphology of the genus, including clarification of male gonopod terminology, is reviewed and defined using scanning electron microscopy and high-quality macrophotographic images, including those in which ultraviolet fluorescence was induced to produce detailed images of morphological structures. Based on the examination of available type material, the following eight species are recognized: (1) Pseudopolydesmus erasus; (2) Pseudopolydesmus canadensis; (3) Pseudopolydesmus collinus; (4) Pseudopolydesmus pinetorum; (5) Pseudopolydesmus minor; (6) Pseudopolydesmus caddo; (7) Pseudopolydesmus paludicolus; and (8) Pseudopolydesmus serratus. The species names Polydesmus neoterus and Polydesmus euthetus are here placed as junior subjective synonyms of Ps. minor (both syn. nov.), and Polydesmus natchitoches is placed as a junior subjective synonym of Ps. pinetorum (syn. nov.).

Scanning electron microscopy of basidiospores of species of Strobilomycetaceae

1971 ◽  
Vol 49 (8) ◽  
pp. 1259-1261 ◽  
Author(s):  
Larry F. Grand ◽  
Royall T. Moore
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
North American ◽  
North American Species ◽  
Surface Features ◽  
The Family ◽  
Similarities And Differences ◽  
Scanning Electron

Basidiospores of 13 North American species of Strobilomycetaceae were examined by scanning electron microscopy. Similarities and differences of surface features among species are discussed in relation to their possible role in the taxonomy of the family.

Seed morphology of perennial taxa of Euphorbia section Pithyusa (Euphorbiaceae) in Turkey

Phytotaxa ◽  
2018 ◽  
Vol 336 (3) ◽  
pp. 263
Author(s):  
İLKER GENÇ ◽  
ŞÜKRAN KÜLTÜR
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Seed Morphology ◽  
Seed Shape ◽  
Seed Surface ◽  
Surface Ornamentation ◽  
Seed Characteristics ◽  
Scanning Electron ◽  
Comprehensive Study

A comprehensive study based on seed morphology of perennial Euphorbia (Euphorbiaceae) sect. Pithyusa species occurring in Turkey is presented. A total of 14 species were studied. Seed characteristics were examined using scanning electron microscopy (SEM) as well as dissecting light microscopy. Significant features are: seed size, seed shape, shape of caruncle and seed surface ornamentation. Three different seed surface types (smooth, pitted, and wrinkled) were observed. Four main seed shapes (ovoid, oblong, quadrangular, and globose), as well as seven types of seed coat ornamentation (reticulate-areolate, areolate, alveolate, falsifoveate, pusticulate, colliculate and smooth) were found. The number of testa cells per 100 µm2 and also its range, from 8–12 to 57–63, are given.

Observations on North American Gomphoneis. III. Gomphoneis septa comb.nov.

1986 ◽  
Vol 64 (11) ◽  
pp. 2764-2768 ◽  
Author(s):  
J. P. Kociolek ◽  
E. F. Stoermer ◽  
L. L. Bahls
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
North American ◽  
Size Range ◽  
Taxonomic Position ◽  
Apical Pore ◽  
Close Relationship ◽  
Ultrastructural Characteristics ◽  
Scanning Electron

The valvar ultrastructure of the diatom Gomphonema septum Mogh. was investigated with scanning electron microscopy and is discussed with regard to the taxonomic position of this species. Ultrastructural features include striae composed of double rows of puncta, presence of a narrow axial plate which is responsible for the image of longitudinal lines, and apical pore fields composed of pores dissimilar in appearance from the puncta. These and other ultrastructural characteristics point to a close relationship between G. septum and members of the genus Gomphoneis. A transfer of Gomphonema septum to Gomphoneis is proposed. Information supplemental to previous observations on the size range and variability of this species is presented.

Mineral concentrations within cells of galls induced by Hemadas nubilipennis (Hymenoptera: Pteromalidae) on lowbush blueberry: evidence from cryoanalytical scanning electron microscopy

1994 ◽  
Vol 72 (9) ◽  
pp. 1387-1390 ◽  
Author(s):  
Giuseppe Bagatto ◽  
Joseph D. Shorthouse
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Key Words ◽  
Osmotic Potential ◽  
Larval Feeding ◽  
Vaccinium Angustifolium ◽  
Lowbush Blueberry ◽  
Insect Gall ◽  
Mineral Concentrations ◽  
Scanning Electron

Cryoanalytical scanning electron microscopy was used to examine cellular concentrations of K, P, S, Mg, Ca, Fe, Cu, Ni, and Au in a planed section of an insect gall induced by Hemadas nubilipennis on shoots of lowbush blueberry. Levels of K varied throughout tissues of the gall, with the highest levels within the cytoplasmically dense nutritive cells lining the larval chambers, storage nutritive cells, and peridermal cells. It is postulated that K increases the osmotic potential and size of nutritive cells, thereby facilitating larval feeding. Nutritive cells also contained elevated levels of P and S. Levels of Cu, Ni, Fe, and Au were elevated in epidermal tissues, especially near the stomata. Key words: gall, blueberry, minerals, cryoanalytical SEM, Hemadas nubilipennis, Vaccinium angustifolium.

Isoetes ×pseudotruncata, a new triploid hybrid from western Canada and Alaska

1996 ◽  
Vol 74 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Donald M. Britton ◽  
Daniel F. Brunton
Keyword(s):  
Electron Microscopy ◽  
British Columbia ◽  
Pacific Coast ◽  
Western Canada ◽  
Triploid Hybrid ◽  
Freshwater Habitat ◽  
Spore Ornamentation ◽  
The Pacific ◽  
Northwestern North America ◽  
Scanning Electron

A new interspecific Isoetes hybrid, I. echinospora Dur. ×I. maritima Underw., is described from Vancouver Island, British Columbia and southern Alaska by means of cytology and the scanning electron microscopy of spores. Isoetes ×pseudotruncata D.M. Britton and D.F. Brunton, hyb.nov. is the name proposed for this taxon. It is triploid and produces only aborted, sterile spores and has spore ornamentation features intermediate between those of its putative parents. Several concentrations of hybrids have been identified, each growing with both parents in shallow, freshwater habitat along the Pacific Coast of northwestern North America. Keywords: Isoetes echinospora, Isoetes maritima, hybrid, British Columbia.

Phyllodistomum umblae (Fabricius) (Digenea, Gorgoderidae) from British Columbia salmonids: a description based on light and scanning electron microscopy

1987 ◽  
Vol 65 (7) ◽  
pp. 1703-1712 ◽  
Author(s):  
T. A. Bakke ◽  
R. E. Bailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
Electron Microscope ◽  
Salmo Salar ◽  
Electron Microscope Study ◽  
Salvelinus Fontinalis ◽  
Salmo Gairdneri ◽  
Scanning Electron Microscope Study ◽  
Scanning Electron

Specimens of Phyllodistomum umblae (Fabricius, 1780) from Oncorhynchus nerka (Walbaum) from the Nautley River, British Columbia, and Salmo gairdneri Richardson from the Stuart River, British Columbia, are described and figured using light microscopy and scanning electron microscopy. Particular emphasis is placed on describing the numbers, types, and arrangement of papillae as seen with scanning electron microscopy. No significant differences were observed between the present Canadian material from O. nerka and S. gairdneri and specimens of P. umblae described from Norway, Sweden, and the U.S.S.R. Thus, P. umblae has a holarctic distribution in salmonids. Phyllodistomum limnosa Sandeman and Pippy, 1967, described from Salmo salar L. and Salvelinus fontinalis (Mitchill) from Newfoundland, is regarded as a synonym of P. umblae. Phyllodistomum lachancei Choquztte, 1947, described from S. fontinalis in Quebec, probably is also a synonym of P. umblae, but a more detailed scanning electron microscope study of the papillae in P. lachancei is required for confirmation.

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