Schistidium relictum (Grimmiaceae, Bryophyta), a new moss species from Northwest North America and Siberia

Phytotaxa ◽  
2017 ◽  
Vol 299 (2) ◽  
pp. 234 ◽  
Author(s):  
TERRY T. MCINTOSH ◽  
HANS H. BLOM ◽  
OXANA I. KUZNETSOVA ◽  
ELENA A. IGNATOVA

Schistidium relictum is described as a new northwest North American and Siberian species of moss. Important distinguishing characters include dull, nearly black plants, with stems densely and evenly foliated, weakly spreading leaves that usually lack awns, and the mostly 1-stratose distal leaf laminae with 2(–3) -stratose margins. The species has a remarkable disjunct distribution pattern with most of the sites where it has been found having been unglaciated during the Pleistocene glaciations. It is restricted to areas with occurrence of calcareous bedrock, especially limestones. It appears to be rather isolated genetically based on molecular studies of total ITS. It is sister to the large clade, ‘Apocarpum’, which consists of species which probably embody its closest known extant relatives.

1983 ◽  
Vol 61 (1) ◽  
pp. 218-223 ◽  
Author(s):  
René J. Belland

The bryophyte floras of eight bryophyte-dominated late snow beds near Bonne Bay, western Newfoundland, were investigated and consisted of 49 species of which 4 are reported new for eastern North America (excluding Greenland): Andreaea nivalis Hook., Kiaeria falcata (Hedw.) Hag., Moerckia blyttii (Moerck) Brockm., and an undescribed species of Trematodon. Five additional species were previously unreported from Newfoundland. Eleven bryophytes from the Newfoundland snow beds are characteristic of this habitat throughout much of their world range, and 13 species show a disjunct distribution pattern between eastern and western North America.


1997 ◽  
Vol 75 (12) ◽  
pp. 2108-2116 ◽  
Author(s):  
Qiuxin Wu ◽  
Gregory M. Mueller

Eastern North America and temperate eastern Asia reportedly share a relatively high number of taxa of macrofungi (mushrooms and relatives), including a number of taxa that have putative eastern North America – temperate eastern Asia disjunct distributions. These reports have been used to imply an affinity between the mycota (fungal equivalent of flora and fauna) of the two regions. To date, however, this affinity has not been examined in detail. A comparison of north temperate macrofungal mycotas was undertaken to examine the similarity between these regions. We used two methods in this study: (i) direct comparison of taxon lists and (ii) calculation of the Simpson Coefficient of similarity from lists of selected taxa. These analyses were based on field work, herbarium records, and published taxonomic treatments for Amanita, Lactarius, Ramaria, and Boletaceae. Results of these analyses document that taxonomic similarity between eastern North America and temperate eastern Asia mycotas can be quite high. In all cases, the calculated similarity values for eastern North America – temperate eastern Asia comparisons are higher than those between either region of North America and Europe or between western North America and eastern Asia. Furthermore, the eastern North American and temperate eastern Asian disjunct distributions of macrofungi are usually limited to the level of species or lower. Key words: biogeography, China, disjunct distribution, macrofungi, North America, Simpson Coefficient.


2002 ◽  
Vol 34 (2) ◽  
pp. 101-111 ◽  
Author(s):  
C. Printzen ◽  
S. Ekman

AbstractThe fruticose lichen Cavernularia hultenii exhibits a strongly disjunct distribution between north-western North America, Newfoundland and north-western Europe. An investigation of its population structure, based on nuclear ITS and IGS DNA sequences, shows that western North America has a higher number of haplotypes than the two other areas. Most of the haplotypes confined to this region are rare and occur outside the area that was affected by Pleistocene glaciations. Three haplotypes are common in all three areas. The high number of haplotypes in western North America might be due to a combination of events during the Pleistocene and Holocene epochs, viz. increased lineage survival by repeated fragmentation of populations and reduced lineage extinction through rapid postglacial expansion and population growth.


Phytotaxa ◽  
2015 ◽  
Vol 219 (3) ◽  
pp. 243 ◽  
Author(s):  
Nawal Shrestha ◽  
Xian-Chun Zhang

The North American shining clubmoss, Huperzia lucidula, was originally thought to be endemic to North America. However it was reported from China by Ren Chang Ching in 1981, and hence was believed to have a disjunct distribution in North America and Asia. Since then, in all Chinese literature H. lucidula has been described as a disjunct taxon, although in North American literature it has nearly always only been reported from eastern North America. The studies on the Chinese taxon are at present insufficient to address this taxonomical and biogeographical disparity. In this study we have attempted to unravel this issue using integrative morphological and molecular analyses. Morphological study included a thorough examination of specimens from the entire distribution range of H. lucidula in the USA, Canada and China following field collections. Molecular study included Maximum Likelihood and Bayesian inference phylogenetical analyses of three chloroplast markers: the genes rbcL and matK and the psbA-trnH intergenic spacer. The results showed distinct morphological differences between the North American and Chinese taxa, sufficient to recognize them as separate species. The molecular results corroborated these findings and supported the separation of the two taxa. Based on our results, the Chinese taxon is neither a variant of H. lucidula nor sister to it and therefore the supposed disjunct distribution of H. lucidula is erroneous and a result of misidentification. The Chinese taxon that was firstly reported by Ching as H. lucidula var. asiatica has been elevated to the species rank and a new combination has been made.


1998 ◽  
Vol 35 (5) ◽  
pp. 504-509 ◽  
Author(s):  
René W Barendregt ◽  
Edward Irving

Magnetostratigraphy indicates that Early Pleistocene glaciations in North America, instead of forming one continuous ice mass from Atlantic to Pacific as they did in the Late Pleistocene, were characterized by eastern and western ice masses separated by a 2000 km wide north-south ice-free corridor down the centre of the continent. We argue, therefore, that the area covered by ice during periods of glaciation, and hence probably ice volume, in North America was considerably less in the first 2 Ma of the late Cenozoic than it was in the last 0.7 Ma. This is consistent with delta 18O records of ocean cores indicating the ice volumes were much less in the earlier than in the later part of the Cenozoic Ice Age.


2019 ◽  
Author(s):  
Mao-Qin Xia ◽  
Ren-Yu Liao ◽  
Jin-Ting Zhou ◽  
Han-Yang Lin ◽  
Jian-Hua Li ◽  
...  

Abstract Background: The inverted repeat-lacking clade (IRLC) of Fabaceae is characterized by loss of an IR region in plastomes. Both the loss of an IR region and the life history may have affected the evolution of the plastomes in the clade. Nevertheless, few studies have been done to test the impact explicitly. Wisteria , an important member of IRLC and has a disjunct distribution between eastern Asia and eastern North America, has confused interspecific relationships and biogeography, which need to elucidate in depth. Results: The plastome of six newly sequenced Wisteria species and a Millettia japonica ranged from 130,116 to 132,547 bp. Phylogenetic analyses recognized two major clades in IRLC: Glycyrrhiza - Millettia - Wisteria clade and a clade containing the remaining genera. North American Wisteria species and Asian species formed reciprocal clades. Within Asian clade, each of the two Japanese species was sister to a species in the Asian continent. A ~16kb inversion from ndh F to ycf 1 in all IRLC species. Wisteria and Millettia japonica have two intron of rps 12 gene but all other IRLC species just have one. Synonymous substitution rates ( d S ) of protein coding genes were higher in the IRLC species than non-IRLC species. Woody species have lower substitutions rates than herbs. Wisteria may have originated in East Asia by the boundary of Oligocene and Miocene and the eastern Asian-eastern North American disjunction formed in the Late Miocene, while two vicariance events formed the disjunct distributions between the Asian continent and the Japanese islands in the Quaternary. Conclusions: In the IRLC clade, Wisteria , Milletia japonica and Glycyrrhiza form a clade to the remaining genera, most of which are herbaceous. Both the loss of one IR region and the herbaceous habit elevated mutation rates of the plastomes. Multiple vicariance events between eastern Asia and eastern North America, and between the Asian continent and the Japanese Islands may have promoted speciation of Wisteria since the Late Miocene. Plastomes contain rich genetic diversity for studying genetic structure and migration of populations in response to climatic changes, which benefits conservation of rare and endangered species.


2002 ◽  
Vol 80 (11) ◽  
pp. 1151-1159 ◽  
Author(s):  
M Dusabenyagasani ◽  
G Laflamme ◽  
R C Hamelin

We detected nucleotide polymorphisms within the genus Gremmeniella in DNA sequences of β-tubulin, glyceraldehyde phosphate dehydrogenase, and mitochondrial small subunit rRNA (mtSSU rRNA) genes. A group-I intron was present in strains originating from fir (Abies spp.) in the mtSSU rRNA locus. This intron in the mtSSU rRNA locus of strains isolated from Abies sachalinensis (Fridr. Schmidt) M.T. Mast in Asia was also found in strains isolated from Abies balsamea (L.) Mill. in North America. Phylogenetic analyses yielded trees that grouped strains by host of origin with strong branch support. Asian strains of Gremmeniella abietina (Lagerberg) Morelet var. abietina isolated from fir (A. sachalinensis) were more closely related to G. abietina var. balsamea from North America, which is found on spruce (Picea spp.) and balsam fir, and European and North American races of G. abietina var. abietina from pines (Pinus spp.) were distantly related. Likewise, North American isolates of Gremmeniella laricina (Ettinger) O. Petrini, L.E. Petrini, G. Laflamme, & G.B. Ouellette, a pathogen of larch, was more closely related to G. laricina from Europe than to G. abietina var. abietina from North America. These data suggest that host specialization might have been the leading evolutionary force shaping Gremmeniella spp., with geographic separation acting as a secondary factor.Key words: Gremmeniella, geographic separation, host specialization, mitochondrial rRNA, nuclear genes.


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