Geographical origins of North American Rhodiola (Crassulaceae) and phylogeography of the western roseroot, Rhodiola integrifolia

2014 ◽  
Vol 41 (6) ◽  
pp. 1070-1080 ◽  
Author(s):  
Heidi J. Guest ◽  
Geraldine A. Allen
Botany ◽  
2014 ◽  
Vol 92 (12) ◽  
pp. 901-910 ◽  
Author(s):  
Joel P. Olfelt ◽  
William A. Freyman

Taxa of Rhodiola L. (Crassulaceae) generally grow in arctic or alpine habitats. Some Rhodiola species are used medicinally, one taxon, Rhodiola integrifolia Raf. subsp. leedyi (Rosend. & J.W.Moore) Moran, (Leedy’s roseroot), is rare and endangered, and the group’s biogeography in North America is intriguing because of distributional disjunctions and the possibility that Rhodiola rhodantha (A.Gray) H.Jacobsen (2n = 7II) and Rhodiola rosea L. (2n = 11II) hybridized to form Rhodiola integrifolia Raf. (2n = 18II). Recent studies of the North American Rhodiola suggest that the group’s current taxonomy is misleading. We analyzed nuclear and chloroplast DNA sequences (internal transcribed spacer (ITS), trnL intron, trnL–trnF spacer, trnS–trnG spacer) from the North American Rhodiola taxa. We combined our data with GenBank sequences from Asian Rhodiola species, performed parsimony, maximum likelihood (ML), and Bayesian phylogenetic analyses, and applied a Bayesian clock model to the ITS data. Our analyses reveal two major Rhodiola clades, suggest that hybridization between R. rhodantha and R. rosea lineages was possible, show two distinct clades within R. integrifolia, and demonstrate that a Black Hills, South Dakota, Rhodiola population should be reclassified as Leedy’s roseroot. We recommend that R. integrifolia be revised, and that the Black Hills Leedy’s roseroot population be managed as part of that rare and endangered taxon.


2020 ◽  
Vol 29 (2) ◽  
pp. 259-264 ◽  
Author(s):  
Hasan K. Saleh ◽  
Paula Folkeard ◽  
Ewan Macpherson ◽  
Susan Scollie

Purpose The original Connected Speech Test (CST; Cox et al., 1987) is a well-regarded and often utilized speech perception test. The aim of this study was to develop a new version of the CST using a neutral North American accent and to assess the use of this updated CST on participants with normal hearing. Method A female English speaker was recruited to read the original CST passages, which were recorded as the new CST stimuli. A study was designed to assess the newly recorded CST passages' equivalence and conduct normalization. The study included 19 Western University students (11 females and eight males) with normal hearing and with English as a first language. Results Raw scores for the 48 tested passages were converted to rationalized arcsine units, and average passage scores more than 1 rationalized arcsine unit standard deviation from the mean were excluded. The internal reliability of the 32 remaining passages was assessed, and the two-way random effects intraclass correlation was .944. Conclusion The aim of our study was to create new CST stimuli with a more general North American accent in order to minimize accent effects on the speech perception scores. The study resulted in 32 passages of equivalent difficulty for listeners with normal hearing.


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

2006 ◽  
Vol 175 (4S) ◽  
pp. 46-47
Author(s):  
Daniel J. Lewinshtein ◽  
K.-H. Felix Chun ◽  
Alberto Briganti ◽  
Hendrik Isbarn ◽  
Eike Currlin ◽  
...  

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