Circaea × intermedia in eastern North America with particular reference to Ontario

1977 ◽  
Vol 55 (23) ◽  
pp. 2919-2935 ◽  
Author(s):  
Erich Haber
Keyword(s):  
North America ◽  
North American ◽  
Chromosome Numbers ◽  
Interspecific Hybrid ◽  
Somatic Chromosome ◽  
Parental Species ◽  
Eastern North America ◽  
Chromosome Counts ◽  
Morphological Differences ◽  
Somatic Chromosome Numbers

Circaea × intermedia Ehrh. in North America is an interspecific hybrid between C. alpina L. and C. lutetiana L. subsp. canadensis Aschers. & Magnus. In spite of the morphological differences that exist between the European and North American subspecies of C. lutetiana, hybrids from both continents are morphologically identical. Documentation of the intermediacy of the hybrid taxon is presented based on the evaluation of the means of 22 characters of specimens from an Ontario locality at which all three taxa are found.Diploid chromosome counts of 2n = 22 are reported for Ontario populations of the hybrid and parental species. The presence of irregular, somatic chromosome numbers are also reported for all three taxa.Distribution maps for all three taxa in eastern North America are included. In the case of C. lutetiana subsp. canadensis, the northern range is sharply delimited by the Precambrian–Paleozoic bedrock boundary.A table of character comparisons and a key to the three taxa summarizes the salient characteristics of the hybrid and the parental species in eastern North America.

Chromosome numbers and sexual compatibility in North America of Rorippa sylvestris (Cruciferae)

1984 ◽  
Vol 62 (3) ◽  
pp. 575-580 ◽  
Author(s):  
Gerald A. Mulligan ◽  
Derek B. Munro
Keyword(s):  
North America ◽  
North American ◽  
Chromosome Numbers ◽  
Interspecific Hybrid ◽  
Field Observations ◽  
Sexual Compatibility ◽  
Intraspecific Crossing

Tetraploid (2n = 32), pentaploid (2n = 40), and hexaploid (2n = 48) plants of Rorippa sylvestris (L.) Besser (Cruciferae) and a natural pentaploid (2n = 40) interspecific hybrid, R. sylvestris × R. palustris (L.) Besser, are recorded for North America. These counts are compared with published information on European plants. Tetraploids are most common in Europe (68 vs. 20%), whereas hexaploids are most common in North America (65 vs. 29%). Although self-incompatible R. sylvestris rarely sets seed in nature, indicating that plants within most sites are genetically the same clone, intraspecific crossing data, chromosome information, and field observations indicate that North American R. sylvestris results from the vegetative introduction of many different genotypes.

Chromosome numbers from pollen in some North American Impatiens (Balsaminaceae)

1974 ◽  
Vol 52 (12) ◽  
pp. 2637-2639 ◽  
Author(s):  
C. C. Chinnappa ◽  
L. S. Gill
Keyword(s):  
North America ◽  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Herbarium Specimens ◽  
Chromosome Counts ◽  
Present Survey ◽  
The One ◽  
Basic Numbers

Chromosome counts for eight species of Impatiens from North American populations have been determined from herbarium specimens. The chromosome number n = 10 for I. ecalcarata Blank, is a new report. It is apparent from the present survey that there are at least three basic numbers (n = 7, 10, and 13) represented in North America as opposed to the one (n = 10) suggested by the earlier workers.

scholarly journals Rebuttal of McFeeters, Ryan and Cullen, 2018, ‘Positional variation in pedal unguals of North American ornithomimids (Dinosauria, Theropoda): A Response to Brownstein (2017)’

2018 ◽  
Vol 6 ◽  
pp. 68-72
Author(s):  
Chase Doran Brownstein
Keyword(s):  
North America ◽  
Early Cretaceous ◽  
North American ◽  
Eastern North America ◽  
Substantial Evidence ◽  
Theropod Dinosaur ◽  
Positional Variation ◽  
Morphological Differences ◽  
Made In

The Arundel Clay of Maryland is among the only Early Cretaceous terrestrial units known from eastern North America. Research on some theropod dinosaur bones from this layer has indicated the presence of two ornithomimosaur taxa in the assemblage. However, a recent paper discussed issues with the definite assignment of any of these unguals to Ornithomimosauria and suggested that morphological differences originally interpreted to be indicative of the presence of two ornithomimosaurs could be explained by positional variation. Here, I show that substantial evidence persists for the presence of two ornithomimosaurs in the Arundel Clay assemblage, even considering the recent description of positional variation in ornithomimosaur pedal unguals. Furthermore, the argument against the confident assignment of these unguals to ornithomimosaurs is shown to be based on oversimplified comparisons that do not take into account the combination of features in the Arundel specimens that allow for their assignment to that clade. Although several small points made in the initial paper describing the Arundel specimens are incorrect or unsubstantiated, the differences between the Maryland unguals are outside the spectrum of positional variation and are indicative of the presence of two ornithomimosaurs in the Arundel Clay assemblage.

NEW CHROMOSOME COUNTS OFBERBERISL. (BERBERIDACEAE) SUGGEST THAT POLYPLOIDY DOES NOT PLAY A SIGNIFICANT ROLE IN THE DIVERSIFICATION OF THE GENUS IN THE NEPAL HIMALAYA

2014 ◽  
Vol 71 (3) ◽  
pp. 297-308 ◽  
Author(s):  
B. Adhikari ◽  
C. A. Pendry ◽  
M. Möller
Keyword(s):  
Significant Role ◽  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
Chromosome Counts ◽  
Nepal Himalaya ◽  
First Time ◽  
Somatic Chromosome Numbers

Chromosomes were counted for nine of the 24 taxa ofBerberis(Berberidaceae) from Nepal, five of which were counted for the first time. The results show that all these species have somatic chromosome numbers of 2n= 28. The absence of polyploids suggests that polyploidy may not have been a major driver of speciation and diversification ofBerberisin the Nepal Himalaya.

New multituberculate mammal from the Early Cretaceous of eastern North America

2013 ◽  
Vol 50 (3) ◽  
pp. 315-323 ◽  
Author(s):  
Richard L. Cifelli ◽  
Cynthia L. Gordon ◽  
Thomas R. Lipka
Keyword(s):  
North America ◽  
Iberian Peninsula ◽  
Early Cretaceous ◽  
North American ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
Relative Length ◽  
Central Position ◽  
Eastern North America ◽  
The North

Multituberculates, though among the most commonly encountered mammalian fossils of the Mesozoic, are poorly known from the North American Early Cretaceous, with only one taxon named to date. Herein we describe Argillomys marylandensis, gen. et sp. nov., from the Early Cretaceous of Maryland, based on an isolated M2. Argillomys represents the second mammal known from the Arundel Clay facies of the Patuxent Formation (Lower Cretaceous: Aptian). Though distinctive in its combination of characters (e.g., enamel ornamentation consisting of ribs and grooves only, cusp formula 2:4, presence of distinct cusp on anterobuccal ridge, enlargement of second cusp on buccal row, central position of ultimate cusp in lingual row, great relative length), the broader affinities of Argillomys cannot be established because of non-representation of the antemolar dentition. Based on lack of apomorphies commonly seen among Cimolodonta (e.g., three or more cusps present in buccal row, fusion of cusps in lingual row, cusps strongly pyramidal and separated by narrow grooves), we provisionally regard Argillomys as a multituberculate of “plagiaulacidan” grade. Intriguingly, it is comparable in certain respects to some unnamed Paulchoffatiidae, a family otherwise known from the Late Jurassic – Early Cretaceous of the Iberian Peninsula.

CHROMOSOME NUMBERS AND TAXONOMIC NOTES ON NORTHERN GRASSES: II. TRIBE FESTUCEAE

1960 ◽  
Vol 38 (2) ◽  
pp. 117-131 ◽  
Author(s):  
Wray M. Bowden
Keyword(s):  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
Bromus Tectorum ◽  
Dactylis Glomerata ◽  
Bromus Inermis ◽  
Festuca Rubra ◽  
Lolium Rigidum ◽  
Voucher Specimens ◽  
Dactylis Glomerata L ◽  
Somatic Chromosome Numbers

Chromosome numbers and voucher specimens are recorded for some collections of the tribe FESTUCEAE Dumort., mainly collected in Canada. The somatic chromosome numbers of the following are recorded: (1a) Arctagrostis arundinacea (Trin.) Beal var. arundinacea, 2n = 28, 2n = 29, and 2n = 30; (1b) Arctagrostis arundinacea (Trin.) Beal var. crassispica Bowden, 2n = 56; (1c) Arctagrostis latifolia (R.Br.) Griseb., 2n = 56. (2) Beckmannia syzigachne (Steud.) Fern., 2n = 14. (3) Brachyelytrum erectum (Schreb.) Beauv., two vars., 2n = 22. (4a) Bromus ciliatus L., 2n = 14; (4b) Bromus inermis Leyss., two subspecies and two vars., 2n = 56; (4e) Bromus kalmii A. Gray, 2n = 14; (4d) Bromus porteri (Coult.) Nash, 2n = 14; (4c) Bromus tectorum L., 2n = 14. (5) Catabrosa aquatica (L.) Beauv. var. laurentiana Fern., 2n = 20. (6) Dactylis glomerata L., 2n = 28. (7) Distichlisstricta (Torr.) Rydb., 2n = 40. (8a) Dupontiafisheri R.Br, subsp. fisheri, 2n = 132; (8b) Dupontia fisheri R.Br, subsp. psilosantha (Rupr.) Hultén, 2n = 44. (9) Eremopoa persica (Trin.) Roshev., 2n = 28. (10a) Festuca altaica Trin., 2n = 28; (10b) Festuca baffinensis Polunin, 2n = 28; (10c) Festuca brachyphylla Schultes, 2n = 42 and one collection, 2n = 44; (10d) Festuca elatior L., 2n = 14; (10e) Festuca obtusa Bieler, 2n = 42; (10f) Festuca prolifera (Piper) Fern. var. lasiolepis Fern., 2n = 50; (10g) Festuca rubra L., 2n = 42; (10h) Festuca saximontana Rydb., 2n = 42; (10i)Festuca scabrella Torr. ex Hook., two vars., 2n = 56 and 2n = 28. (11a) Glyceria borealis (Nash) Batchelder, 2n = 20; (11b) Glyceria canadensis (Michx.) Trin., 2n = 60; (11c) Glyceria grandis S. Wats., 2n = 20; (11d) Glyceria melicaria (Michx.) Hubb., 2n = 40; (11e) Glyceria pulchella (Nash) K. Schum., 2n = 20; (11f) Glyceria striata (Lam.) Hitchc, 2n = 20; (11g) Glyceria × gatineauensis Bowden (G. melicaria × G. striata), 2n = 30; (11h)Glyceria × ottawensis Bowden (G. canadensis × G. striata), three nothomorphs, 2n = 42, 2n = 46, and 2n = 48. (12) Lolium rigidum Gaud., 2n = 14. (13a) Phippsiaalgida (Sol.) R.Br., 2n = 28; (13b) Phippsia concinna (Th. Fries) Lindeb., 2n = 28. (14) Pleuropogon sabinei R.Br., 2n = 42. (15) Schizachnepurpurascens (Torr.) Swallen, 2n = 20. (16) Torreyochloa fernaldii (Hitchc.) Church, 2n = 14.

scholarly journals Badania kariologiczne nad dwoma gatunkami rodzaju Sparganium L. [Karyological studies in two species of the genus Sparganium]

2015 ◽  
Vol 40 (1) ◽  
pp. 143-148
Author(s):  
K. Bijok ◽  
E. Adamkiewicz
Keyword(s):  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
Somatic Chromosome Numbers

The somatic chromosome numbers 2n = 30 for <em>Sparganium neglectum</em> and <em>S. minimum</em> was established. The karyotype of the first species consist of 8 iso- and 7 heterobronchial chromosomes and the reverse is true for the second species. In metabolic nuclei 30 chromocentres are visible.

scholarly journals Six new species and reports of Hydnum (Cantharellales) from eastern North America

MycoKeys ◽  
2018 ◽  
Vol 42 ◽  
pp. 35-72 ◽  
Author(s):  
Rachel A. Swenie ◽  
Timothy J. Baroni ◽  
P. Brandon Matheny
Keyword(s):  
North America ◽  
North American ◽  
Phylogenetic Analyses ◽  
Eastern North America ◽  
Phylogenetic Species ◽  
Additional Species ◽  
Taxonomic Descriptions ◽  
Molecular Phylogenetic ◽  
Herbarium Collections ◽  
Environmental Sequences

Five species of Hydnum have been generally recognized from eastern North America based on morphological recognition: H.albidum, H.albomagnum, H.repandum and varieties, H.rufescens, and H.umbilicatum. Other unique North American species, such as H.caespitosum and H.washingtonianum, are either illegitimately named or considered synonymous with European taxa. Here, seventeen phylogenetic species of Hydnum are detected from eastern North America based on a molecular phylogenetic survey of ITS sequences from herbarium collections and GenBank data, including environmental sequences. Based on current distribution results, sixteen of these species appear endemic to North America. Of these, six species are described as new: H.alboaurantiacum, H.cuspidatum, H.ferruginescens, H.subconnatum, H.subtilior, and H.vagabundum. Geographic range extensions and taxonomic notes are provided for five additional species recently described as new from eastern North America. A new name, H.geminum, is proposed for H.caespitosum Banning ex Peck, non Valenti. Overall, species of Hydnum are best recognized by a combination of morphological and molecular phylogenetic analyses. Taxonomic descriptions are provided for seventeen species, including epitype designations for H.albidum, H.albomagnum, and H.umbilicatum, taxa described more than 100 years ago, and molecular annotation of the isotype of H.washingtonianum. Photographs and a key to eastern North American Hydnum species are presented.

Telephinaand Other Trilobites from the Pratt Ferry Beds, Ordovician of Alabama, U.S.A.

2014 ◽  
Vol 88 (3) ◽  
pp. 545-555 ◽  
Author(s):  
Frederick C. Shaw
Keyword(s):  
North America ◽  
North American ◽  
Original Description ◽  
Eastern North America ◽  
Zone Boundary ◽  
Middle Ordovician ◽  
Conodont Zone ◽  
Stratigraphic Range ◽  
Single Locality

The Pratt Ferry beds are a three meter thick bioclastic carbonate unit containing thePygodus serrus–P. anserinusconodont zone boundary and lying just below theNemagraptus gracilisgraptolite zone at a single locality in Alabama.TelephinaMarek at Pratt Ferry and other eastern North American localities is represented by at least six species. These are judged widespread and in part conspecific with Scandinavian or Asian forms of similar age. Most of the fifteen Appalachian telephinid species proposed by Ulrich (1930) are reviewed and some synonymized.BevanopsisCooper is present, extending its stratigraphic range viaB. buttsi(Cooper). The original description ofCeraurinella buttsiCooper is augmented. Other recorded but poorly represented genera includeAmpyxina,Arthrorhachis,Calyptaulax,Hibbertia,Lonchodomas,Mesotaphraspis,Porterfieldia, andSphaerexochus. The entire faunule represents a mixture of ‘inshore’ and ‘offshore’ or planktonic faunal elements rarely seen elsewhere in the latest Middle Ordovician (Darriwilian) of eastern North America.

SOMATIC CHROMOSOME NUMBERS IN CERTAIN TRIFOLIUM SPECIES

1972 ◽  
Vol 14 (1) ◽  
pp. 139-145 ◽  
Author(s):  
M. K. Anderson ◽  
N. L. Taylor ◽  
G. B. Collins
Keyword(s):  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
Karyotype Analyses ◽  
Somatic Chromosome Numbers

In the present study chromosome numbers of 13 Trifolium species were determined, making a total of 155 species for which chromosome numbers have been reported. Four species which have been reported only once were confirmed. Eleven of the 17 species observed have 16 chromosomes (n = 8). T. bocconei Savi was found to have 12 chromosomes (n = 6) and T. desvauxii Boess. and Bl. was found to have 10 chromosomes (n = 5). Karyotype analyses of T. bocconei and T. desvauxii revealed that the chromosomes of each species could be differentiated on the basis of arm ratios and chromosome lengths.

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