Natural interspecific hybridization between sexual and apogamous species of the beech fern genus Phegopteris Fée

1972 ◽  
Vol 50 (6) ◽  
pp. 1295-1300 ◽  
Author(s):  
Gerald A. Mulligan ◽  
Lionel Cinq-Mars ◽  
William J. Cody
Keyword(s):  
North America ◽  
Interspecific Hybridization ◽  
Interspecific Hybrid ◽  
Genetic Material ◽  
Female Gamete ◽  
Eastern North America ◽  
Natural Hybrid ◽  
Sexual Species

A clone of beech fern found growing on a mountain near Rougemont in Rouville County of Quebec is shown to be a natural hybrid between two species of Phegopteris that grow together at that location, the circumboreal species P. polypodioides Fée and a species endemic to eastern North America, P. hexagonoptera (Michx.) Fée. Phegopteris polypodioides is shown to be an apogamous triploid (2n = 90), P. hexagonoptera a sexual diploid (2n = 60), and the interspecific hybrid between these two species an apogamous tetraploid (2n = 120). It was concluded that the natural hybrid was produced by the union of a motile gamete, containing 90 chromosomes, from an antheridium on a prothallus of apogamous P. polypodioides with a female gamete, containing 30 chromosomes, on a prothallus of sexual P. hexagonoptera. This is the second report of interspecific hybridization between sexual and apogamous species of ferns. The morphology of both parents and the hybrid supports the conclusion that the apogamous species contributed more genetic material to the hybrid than did the sexual species. It is suggested that this hybrid probably occurs at other locations where the ranges of P. polypodioides and P. hexagonoptera overlap.

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.

INTERSPECIFIC HYBRIDIZATION IN LOBELIA L. SECTION LOBELIA

1961 ◽  
Vol 39 (7) ◽  
pp. 1679-1693 ◽  
Author(s):  
Wray M. Bowden
Keyword(s):  
Interspecific Hybridization ◽  
Interspecific Hybrid ◽  
Natural Hybrid ◽  
Negative Results

The results of about 1400 pollinations that involved the 21 species of Lobelia L. sect. Lobelia are reported. The bispecific combinations that gave positive or negative results are recorded. Thirty-three different species combinations are represented in the artificial interspecific hybrid populations. Two of these hybrids have been reported by previous authors.Lobelia × rogersii hybr. nov. (L. brevifolia × L. puberula) is described. Numerous natural hybrid specimens were examined and the parentage was confirmed experimentally. Some plants of L. × rogersii were pollen-sterile; other plants were partly self-fertile.

Chemotaxonomic studies on hybrids of Dryopteris in eastern North America

1975 ◽  
Vol 53 (15) ◽  
pp. 1554-1567 ◽  
Author(s):  
C.-J. Widén ◽  
D. M. Britton ◽  
W. H. Wagner Jr. ◽  
F. S. Wagner
Keyword(s):  
North America ◽  
Diploid Species ◽  
Eastern North America ◽  
Sexual Species ◽  
Naturally Occurring ◽  
Evolutionary Studies ◽  
First Time

Sixty-nine specimens of Dryopteris were analyzed for phloroglucinols. Thirty-nine were referable to 9 sexual species and 30 were referable to 17 hybrid combinations. Ten hybrid combinations were analyzed for the first time. These are D. celsa × goldiana, D. celsa × clintoniana, D. assimilis × intermedia, D. campyloptera × intermedia, D. goldiana × intermedia, D. celsa × intermedia, D. assimilis × marginalis, D. campyloptera × marginalis, D. marginalis × spinulosa, and D. celsa × marginalis. Twenty-three naturally occurring hybrid taxa have now been analyzed and the use of the phloroglucinol system for systematics and evolutionary studies is assessed. Dryopteris marginalis and its hybrids have the most useful spectra of phloroglucinols for analysis. The hybrids in this group show the best additive spectra of the 23 hybrid taxa studied. Dryopteris marginalis, although a basic diploid species, is not considered to have given rise to derived alloploids.

The Identification and Study of Indian Shell Middens in Eastern North America: 1643–1861

1986 ◽  
Vol 6 (3) ◽  
pp. 227-243 ◽  
Author(s):  
Andrew L. Christenson
Keyword(s):  
Nineteenth Century ◽  
Civil War ◽  
North America ◽  
East Coast ◽  
Eastern North America ◽  
Shell Midden ◽  
Shell Middens ◽  
Work Done

Although the interest in shell middens in North America is often traced to reports of the discoveries in Danish kjoekkenmoeddings in the mid-nineteenth century, extensive shell midden studies were already occurring on the East Coast by that time. This article reviews selected examples of this early work done by geologists and naturalists, which served as a foundation for shell midden studies by archaeologists after the Civil War.

HAVE WE SEEN THE LARGEST EARTHQUAKES IN EASTERN NORTH AMERICA?

2018 ◽  
Author(s):  
James S. Neely ◽  
◽  
Seth Stein ◽  
Miguel Merino ◽  
John Adams
Keyword(s):  
North America ◽  
Eastern North America
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