Chemotaxonomic studies on Dryopteris from Quebec and eastern North America

1974 ◽  
Vol 52 (3) ◽  
pp. 627-638 ◽  
Author(s):  
Donald M. Britton ◽  
Carl-Johan Widén
Keyword(s):  
North America ◽  
Diploid Species ◽  
Eastern North America ◽  
Triploid Hybrid ◽  
Tetraploid Species ◽  
Phloroglucinol Derivatives

Chromatographic analyses of the phloroglucinol derivatives in 213 collections of Dryopteris from eastern North America and particularly Quebec were made. The taxa studied were two diploid species, D. assimilis S. Walker and D. intermedia (Muhl.) A. Gray; two tetraploids, D. spinulosa Watt and D. campyloptera Clarkson; the triploid hybrid, D. × triploidea Wherry; all in the D. spinulosa complex. Also studied were the tetraploid species D. cristata (L.) Gray, the triploid hybrid, D. × boollii (Tuckerm.) Underwood, the tetraploid species, D. filix-mas (L.) Schott, and the diploid D. marginalis (L.) A. Gray. Both glandular and glabrous specimens of D. assimilis and D. campyloptera were studied, but it was found that these characteristics were not necessarily correlated with the presence or absence of phloroglucinols. Dryopteris campyloptera consists of plants which may be "phloroglucinol rich" or "phloroglucinol poor," while D. assimilis and D. spinulosa are both low in phloroglucinol content as compared to European plants. The geographical ranges of the species is briefly considered and the chemical uniformity of some taxa and the variability of others is discussed.

A chromatographic and cytological study of Dryopteris dilatata in eastern North America

1969 ◽  
Vol 47 (9) ◽  
pp. 1337-1344 ◽  
Author(s):  
Carl-Johan Widén ◽  
Donald M. Britton
Keyword(s):  
North America ◽  
Genome Analysis ◽  
Chromatographic Analysis ◽  
Cytological Study ◽  
Eastern North America ◽  
Ancestral Genome ◽  
Evolutionary Patterns ◽  
Phloroglucinol Derivatives

The phloroglucinol derivatives found in the rhizomes of Dryopteris intermedia Gray, diploid D. "dilatata", and D. campyloptera Clarkson, all from eastern North America, are compared and contrasted with those found in D. assimilis S. Walker, D. dilatata A. Gray, and D. spinulosa Watt from Europe, as well as diploid D. “dilatata” from Alaska. The presence or absence, and the morphology, of internal secreting hairs in these species was useful for comparing taxa and suggesting evolutionary patterns. Chromatographic analysis gives many more categories or finer divisions of D. dilatata s.l. than does genome analysis, which has suggested that D. assimilis, D. intermedia, and western D. “dilatata” represent the same ancestral genome.

A chromatographic and cytological study of Dryopteris dilatata in North America and eastern Asia

1971 ◽  
Vol 49 (2) ◽  
pp. 247-258 ◽  
Author(s):  
Carl-Johan Widén ◽  
Donald M. Britton
Keyword(s):  
North America ◽  
Chromatographic Analysis ◽  
Cytological Study ◽  
Eastern North America ◽  
Western North America ◽  
European Studies ◽  
Eastern Asia ◽  
Phloroglucinol Derivatives ◽  
Derivatives Of

A chromatographic analysis of the phloroglucinol derivatives of 123 collections of Dryopteris intermedia Gray (2x), D. assimilis S. Walker (2x) from western North America, D. "dilatata" from eastern North America (2x), D. "austriaca" from Japan and Kamchatka, "Aspidium dilatatum" from Siberia, D. campyloptera Clarkson (4x) from eastern North America, D. spinulosa Watt (4x) from North America, the hybrids D. "dilatata" × campyloptera (3x) and D. intermedia × spinulosa (3x) is presented. D. "dilatata" from eastern North America has an extremely variable phloroglucinol content, which limits the utility of the analysis for taxonomy. The chromatographic and cytological results are discussed in connection with the evolution of the two tetraploid taxa, D. campyloptera and D. spinulosa. The intra-specific variability of each taxon is discussed and compared with the extensive European studies. The material investigated may be considered to belong to the following species: D. intermedia Gray (2x), D. assimilis S. Walker (2x), D. campyloptera Clarkson (4x), and D. spinulosa Watt (4x). Only two different ancestral genomes are considered to be present in these four species, one in the first three species, and two in D. spinulosa.

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.

Comparative Analysis of Genetic and Morphological Variation within the Platanthera hyperborea Complex (Orchidaceae)

2020 ◽  
Vol 45 (4) ◽  
pp. 767-778
Author(s):  
Eranga Wettewa ◽  
Nick Bailey ◽  
Lisa E. Wallace
Keyword(s):  
North America ◽  
Diploid Species ◽  
Morphological Characters ◽  
Evolutionary Patterns ◽  
Founding Population ◽  
Multiple Origins ◽  
Geographic Structure ◽  
Species Complexes ◽  
Nuclear Its ◽  
Cryptic Taxa

Abstract—Species complexes present considerable problems for a working taxonomy due to the presence of intraspecific variation, hybridization, polyploidy, and phenotypic plasticity. Understanding evolutionary patterns using molecular markers can allow for a more thorough assessment of evolutionary lineages than traditional morphological markers. In this study, we evaluated genetic diversity and phylogenetic patterns among taxa of the Platanthera hyperborea (Orchidaceae) complex, which includes diploid (Platanthera aquilonis) and polyploid (Platanthera hyperborea, P. huronensis, and P. convallariifolia) taxa spanning North America, Greenland, Iceland, and Asia. We found that three floral morphological characters overlap among the polyploid taxa, but the diploid species has smaller flowers. DNA sequence variation in a plastid (rpL16 intron) and a nuclear (ITS) marker indicated that at least three diploid species have contributed to the genomes of the polyploid taxa, suggesting all are of allopolyploid origin. Platanthera convallariifolia is most like P. dilatata and P. stricta, whereas P. huronensis and P. hyperborea appear to have originated from crosses of P. dilatata and P. aquilonis. Platanthera huronensis, which is found across North America, has multiple origins and reciprocal maternal parentage from the diploid species. By contrast, P. hyperborea, restricted to Greenland and Iceland, appears to have originated from a small founding population of hybrids in which P. dilatata was the maternal parent. Geographic structure was found among polyploid forms in North America. The area of Manitoba, Canada appears to be a contact zone among geographically diverse forms from eastern and western North America. Given the geographic and genetic variation found, we recommend continued recognition of four green-flowered species within this complex, but caution that there may be additional cryptic taxa within North America.

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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