scholarly journals Relationships And Taxonomic Status Of The North American Natricine Snake Genera Liodytes, Regina, and Clonophis

Author(s):  
Douglas A Rossman
2009 ◽  
Vol 13 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Oksana Yavorska

The North American species of the non-native flora of the Kyiv urban area (Ukraine): a checklist and analysisThis paper presents an annotated checklist of the North American species established in the flora of the Kyiv urban area (KUA). For each taxon, the following data are provided: distribution in the area, degree of naturalization, period of immigration, mode of immigration and ecological characteristics. The group of the North American neophytes consists of 114 species belonging to 71 genera and 36 families and 23 cultivated species and of problematic taxonomic status. Among them prevail ergasiophytes (26%), ergasiophygophytes (22%) and ephemerophytes (19%). The majority of neophytes (47%) have spread over all types of ecotopes. Among them 12 species are invasive alien plants in the KUA.


1991 ◽  
Vol 69 (10) ◽  
pp. 2261-2270 ◽  
Author(s):  
Laurie L. Consaul ◽  
Suzanne I. Warwick ◽  
John McNeill

The Polygonum lapathifolium complex consists of populations that are widely distributed in the Northern Hemisphere and that have been classified at different taxonomic levels. Allozyme data were used to test the current North American taxonomic status of members of the complex (including P. lapathifolium var. lapathifolium, P. lapathifolium var. salicifolium, and P. scabrum) and to verify diploidy in the P. lapathifolium complex and polyploid origins of the morphologically similar P. persicaria and P. pensylvanicum. Of the 15 enzyme systems surveyed in 50 populations of the complex, only 3 of the 23 loci (Acon, Lap, and Skdh) were polymorphic in the North American populations and a total of 6 loci in European populations. Fifteen multilocus genotypes were evident in the complex. Four genotypes (all with Lap-10.67 were exclusive to North American populations of P. lapathifolium, providing support for a North American element of the complex. Nine genotypes (all with Lap-10.63) were found in North American and European populations of P. scabrum, all European populations of the P. lapathifolium complex, and three populations of North American P. lapathifolium var. lapathifolium. Lap-10.67 was also found in the native tetraploid P. pensylvanicum, whereas Lap-10.63 was found in the introduced tetraploid P. persicaria. Genetic distances among populations did not support the current taxonomic divisions within the complex, nor did it support separate species status of P. scabrum. Allozyme data provided support for the allotetraploid origins of P. pensylvanicum and P. persicaria, with members of the P. lapathifolium complex as one of the parents of each. Key words: Polygonum lapathifolium, Polygonum scabrum, Polygonum pensylvanicum, Polygonum persicaria, allozymes.


1981 ◽  
Vol 59 (5) ◽  
pp. 563-571 ◽  
Author(s):  
Diana G. Horton

A critical study of the differentiating features of the North American populations of Timmia sibirica Lindb. et Arnell and T. norvegica Zett. reveals that populations with structure intermediate between these two taxa occur. Although from widespread localities, the intermediate specimens seem limited in number and T. sibirica and T. norvegica quite commnonly occur in mixed populations with no evidence of any intergradation. Therefore, it is concluded that the two taxa ought to be regarded as distinct species. The taxonomically important character-states of upper leaf cells and costa of T. sibirica. T. norvegica, and of the intermediate populations are illustrated with scanning elecron micrographs. The habitat of T. sibirica, like that of T. norvegica, is invariably on strongly calcareous substrates adjacent to waterfalls, along streams, or in low-lying tundra. The North American distribution of T. sibirica is mapped, including previously unreported localities as far south as 51° N in the Canadian Rocky Mountains.


2015 ◽  
Vol 47 (3) ◽  
pp. 167-182 ◽  
Author(s):  
Gary B. Perlmutter ◽  
Shirley C. Tucker ◽  
Eimy Rivas Plata ◽  
Philippe Clerc ◽  
Robert Lücking

AbstractRecently collected specimens of the crustose lichenMelaspilea demissafrom south-eastern USA have been compared with those ofMelaspileaspp. previously determined from North America. A review of both the historical and contemporary treatments of this species is provided. A lectotype was selected from the type collection ofM. demissain FH and is here proposed as it best matches incomplete citations in the original treatment. We also discuss the nomenclatural and taxonomic status of the nameOpegrapha cymbiformisvar.deformis(considered a synonym ofM. gibberulosa). North American specimens ofM. gibberulosawere found to be misidentifications, as were specimens attributed toM. lentiginosula,M. mesophlebiaandM. octomera. We therefore recommend that these species be removed from the North American lichen checklist. We also present a key to North AmericanMelaspilea.


2010 ◽  
Vol 41 (4) ◽  
pp. 303-316 ◽  
Author(s):  
David Lightfoot ◽  
Kelly Miller ◽  
William Edelman

AbstractThe phylogenetic placement of the North American band-winged grasshopper Shotwellia isleta (Gurney 1940) (Orthoptera: Acrididae: Oedipodinae) has been investigated. This rare and unique species of grasshopper belongs to a monotypic genus known only from a few isolated locations in the Chihuahuan Desert of Mexico and New Mexico, USA. The taxonomic status of Shotwellia has been uncertain and historically classified in very different ways relative to other genera. We conducted the first molecular phylogenetic cladistic analysis of Shotwellia and of the Chortophaga (Saussure) genus group in which it is currently classified, using three mitochondrial genes (16S, 12S and cytochrome c oxidase II), 14 morphological characters and two behavioral characters. Our analysis supports the current monotypic status of the genus Shotwellia within the Chortophaga genus group and indicates that Shotwellia is sister to the other genera in that group. Shotwellia isleta is a species of conservation concern, and our field sampling indicates that it is a rare specialist of freshwater ephemeral desert lake beds that are being impacted by human activity. Understanding the phylogeny of S. isleta provides a basis from which biological, evolutionary and conservation inferences can be made.


2004 ◽  
Vol 53 (1-6) ◽  
pp. 99-104 ◽  
Author(s):  
A. Kormutak ◽  
B. Vookova ◽  
B. Ziegenhagen ◽  
H. Y. Kwon ◽  
Y. P. Hong

AbstractUsing PCR-RFLP analysis, a comparative study on the restriction site polymorphism within 8 genes and regions of the Abies chloroplast DNA has been conducted covering 15 Asian, 6 North American and 7 Mediterranean species. A variable degree of divergence was observed among individual species of a given region as well as between geographical groups. A group of the Mediterranean firs, consisting of closely related species, differed profoundly from both Asian and North American representatives. Although a higher level of restriction site variants was detected among the Asian firs, two thirds of them were allocated to the difference between A. mariesii and the other Asian firs. The North American species exhibited the highest level of polymorphism resulting in several subgroups on a cladogram. At the individual species level, the Asian species A. mariesii and the North American species A. lasiocarpa diverged conspicuously from their counterparts in their respective regions. The results of restriction site polymorphism analysis are discussed with ragard to crossability and taxonomic status of individual species.


2006 ◽  
Vol 84 (3) ◽  
pp. 453-468 ◽  
Author(s):  
Chang-Shook Lee ◽  
Stephen R. Downie

The genus Cicuta (Apiaceae tribe Oenantheae Dumort.) is the most virulently poisonous group of flowering plants native to the north temperate zone. A recent treatment recognized four species ( C. bulbifera L., C. douglasii (DC.) J.M. Coult. & Rose, C. maculata L., and C. virosa L.), with C. maculata divided into four varieties. We present results of phylogenetic analyses of the nuclear ribosomal DNA (rDNA) internal transcribed spacer (ITS) locus and the region bounded by the chloroplast genes psbI and trnK 5′ exon to determine taxonomic limits and relationships among these taxa, and to assess the taxonomic status of C. douglasii, a polyploid thought to be derived from C. maculata and C. virosa. Cicuta bulbifera and C. virosa are each resolved as monophyletic, the latter is a sister group to all other species. Discordance between the ITS- and plastid-derived phylogenies and lack of resolution in the ITS trees preclude unequivocal hypotheses of relationship; all trees do suggest, however, that the allotetraploid C. douglasii is polyphyletic and possibly polytopic, with all examined accessions but one nested within C. maculata. This single outstanding accession is from California and, pending further study, might warrant recognition as a distinct species. The diploid C. bulbifera may also be of hybrid origin, as revealed by significant discordance between data sets. Within C. maculata, only the western North American var. angustifolia Hook. is resolved in the ITS trees. In the cpDNA trees, C. maculata var. angustifolia comprises a strongly supported clade with C. maculata var. bolanderi (S. Watson) G.A. Mulligan and C. douglasii, both of primarily western North American distribution. The eastern North American taxa, C. maculata vars. maculata and victorinii (Fernald) B. Boivin, also comprise a clade, sister group to C. bulbifera.


2006 ◽  
Vol 175 (4S) ◽  
pp. 511-512
Author(s):  
David G. McLeod ◽  
Ira Klimberg ◽  
Donald Gleason ◽  
Gerald Chodak ◽  
Thomas Morris ◽  
...  

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