scholarly journals EUPHORIA DAVIDII SUBILS (EUPHORBIACEAE) IN FLORA OF RAILWAY TRACKS OF DNIESTER BAY BAR

2021 ◽  
Vol 26 (2(49)) ◽  
pp. 101-108
Author(s):  
О. Yu. Bondarenko ◽  
S. L. Myronov

Aim. Anthropogenically transformed ecotopes act as a centre for existance of many adventive species. The distribution of North-American species Euphorbia davidii subsp. Poinsettia across various continents is often attributed to the export of grain. For some time scientists have been bringing up the issue about identification of plants E. davidii in new territories, because the species is morphologically similar to E. dentata agg. The species E. davidii is characterised by a high invasive potential, it is a neophyte. In Ukraine the species is represented by separate localities almost throughout the country. It is related to sectors of ports, railway tracks, and abandoned lands. Methods. In the year 2021, by means of route method, in sectors of railway tracks of the Dniester bay bar, between the railway stops Karolina-Buhas and Soniachna (total length is up to eight kilometers) seven localities of E. davidii were distinguished; the coordinates of the locations are listed in the publication. The examined ecotopes are characterised by a crushed stone substratum, with higher temperatures, and also by specific vibrational, insolational and hydrological modes. Results. Both inconsiderable in number of plants localities (32 exemplars) and zones, where the number of plants reaches over 2000 are represented. The extent of habitats ranges from 2 to 20 meters. The height of particular, the most developed individuals constituted 20 cm. As a rule, in the inter-rail space there is a considerably smaller number of plants, however, they are better developed, well-branched and have more inflorescences with fruits. Conclusions. A number of plants from the southern slopes of the railways is typically bigger, however, the plants on the southern slopes (in comparison with the northern ones) are worse developed, branch out less and, at the time of conducting the research were represented by a smaller number of generative individuals. In sandy sectors of the bay bar adjoining the railway tracks the plants E. davidii were almost not noticed. The individuals found in the above-mentioned sectors are characterised by stunted growth, a single stem, almost did not bloom, and did not produce seeds.  

1961 ◽  
Vol 39 (1) ◽  
pp. 21-33 ◽  
Author(s):  
C. Frankton ◽  
R. J. Moore

The morphology and specific differences of Cirsium undulatum (Nutt.) Spreng. and of C. flodmanii (Rydb.) Arthur are described and their Canadian distributions are reported in detail. The chromosome numbers are C. undulatum f. undulatum and f. album Farwell, 2n = 26; C. flodmanii f. flodmanii and f. albiflorum D. Löve, 2n = 22. The origin of four North American species of Cirsium that do not follow the world-wide base number 17 is discussed; it is postulated that reduction in number has occurred by translocations. The chromosomes of species with reduced numbers are larger than those of the unreduced species but the total length of the chromosomes of both groups is approximately the same.


2014 ◽  
Vol 55 (3) ◽  
pp. 367-384 ◽  
Author(s):  
Małgorzata Guzikowa ◽  
Paul F. Maycock

The geographical distributions of three adventive species of North American goldenrods (<em>S. canadensis</em> L. s.l., <em>S. gigantea</em> Ait. and S. <em>graminifolin</em> (L.) Salisb.) throughout Poland are presented. The history of escape, initial establishent and subsequent spread are documented on the basis of almost 1400 herbarium collections and site records of the authors. Of the three species <em>S. gigantea</em> is the most aggressive <em>S. cunadensis</em> has continued to spread vigorously. but <em>S. graminifolia</em> has barely moved beyond its initial area of establishment. The first two species occur essentially throughout Poland. having expanded from centers in southwestern Poland in the decade between 1840 to 1850. Both of these plants are spreading rapidly and producing vigorous populations which thrive in disturbed and semi-disturbed environments and <em>S. gigantea</em> seems to have now attained the capability of invading stabilized habitats and communities. They are in the process of becoming a serious threat to many natural environments and ecosystems in Poland.


1938 ◽  
Vol 70 (11) ◽  
pp. 230-232 ◽  
Author(s):  
C. Stuart Walley

The following notes were assembled in arranging the Protarchoides material in the National Collection. In establishing the identity of Protarchoides mellipes (Prov.) it has been found necessary to synonymize one species. A species allied to mellipes is described as new and a table is provided for the separation of the four known North American species. The recording of Trichiosoma as host for a member of this genus is further evidence of the close relationship of the genus with Protarchus Foer.


1965 ◽  
Vol 97 (2) ◽  
pp. 193-198 ◽  
Author(s):  
G. R. Hopping

AbstractGroup VII of North American Ips contains I. thomasi, new species, I. borealis Swaine and I. swainei R. Hopping. They are less than 4.0 mm. long and females have the front of the head or at least the vertex smooth and shining, impunctate, or with very fine sparse punctures; males are more coarsely granulate-punctate on the frons. The species are described and a key is given. All breed in Picea in Canada and northern United States.


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