scholarly journals Reassessing the taxonomic diversity of Plagiothecium section Orthophyllum in the North American bryoflora

Brittonia ◽  
2020 ◽  
Vol 72 (4) ◽  
pp. 337-350 ◽  
Author(s):  
Grzegorz J. Wolski

AbstractAt the beginning of the twentieth century, Plagiothecium nemorale s.l. and P. succulentum, both belonging to P. sect. Orthophyllum, were considered to be distributed across almost the entire Northern Hemisphere. However, in the mid-twentieth century these taxa were recircumscribed resulting in their exclusion from the North American bryoflora and restricting their distributions to Asia and Europe, and in the case of Plagiothecium nemorale s.l., also North Africa. More recently, it was found that P. nemorale s.l. is a taxonomic complex comprising three distinct species: P. nemorale s.s., P. longisetum, and P. angusticellum. I revised the North American material of P. section Orthophyllum deposited in three herbaria (NY, FH, F) and found that five examined taxa of the section are present in the North America. Two of the species P. angusticellum and P. longisetum, have not been recorded from North America previously, while two others, P. nemorale and P. succulentum, had not been listed in the North American bryoflora for 50 years. One taxon is new for the U.S.A. – P. succulentum f. propaguliferum. Here I provide detailed descriptions of the anatomical and morphological features of the recorded taxa along with photographic documentation of their most important characteristics. I also summarize their known distributions in North America and ecological preferences and provide a key for their identification.

1988 ◽  
Vol 120 (S144) ◽  
pp. 13-24 ◽  
Author(s):  
William L. Peters

AbstractThe complex origins of the North American Ephemeroptera fauna extended from the Lower Permian to the Recent. This paper discusses origins of North American genera of the cosmopolitan family Leptophlebiidae with a few examples from other mayfly families. The two extant subfamilies, Leptophlebiinae and Atalophlebiinae, probably evolved at least by the mid-Cretaceous, or about 100 million years before present. The primitive Leptophlebiinae are distributed throughout most of the Northern Hemisphere and the ancestors of the Leptophlebia–Paraleptophlebia complex within this subfamily dispersed widely by the North Atlantic route as early as the mid-Cretaceous and later probably by northern trans-Pacific dispersals through Beringia. The ancestors of Habrophlebia dispersed through the North Atlantic route at an early time, but the vicariant distribution of Habrophlebiodes in several areas of the Oriental Region and eastern North America correlates with the Arcto-Tertiary forest that covered most of the Northern Hemisphere including Beringia from the Early Tertiary into the Pleistocene. Within the nearly cosmopolitan Atalophlebiinae, Traverella is austral in origin and probably dispersed north through the Mexican Transition Zone during the mid-Tertiary as an ancient dispersal and then dispersed to its northern and eastern limits following the last Pleistocene deglaciation by way of the Missouri River tributaries. Thraulodes and Farrodes are both austral in origin and probably dispersed north through the Mexican Transition Zone during the Early Pleistocene as a relatively recent dispersal. The origins of Choroterpes sensu stricto and Neochoroterpes in North America are unknown. The mayfly fauna of the West Indies is Neotropical in origins, and no affinities between the West Indies and North America through Florida have ever been confirmed.


2019 ◽  
Vol 32 (18) ◽  
pp. 5799-5814 ◽  
Author(s):  
Nicholas J. Lutsko ◽  
Jane Wilson Baldwin ◽  
Timothy W. Cronin

Abstract The impact of large-scale orography on wintertime near-surface (850 hPa) temperature variability on daily and synoptic time scales (from days to weeks) in the Northern Hemisphere is investigated. Using a combination of theory, idealized modeling work, and simulations with a comprehensive climate model, it is shown that large-scale orography reduces upstream temperature gradients, in turn reducing upstream temperature variability, and enhances downstream temperature gradients, enhancing downstream temperature variability. Hence, the presence of the Rockies on the western edge of the North American continent increases temperature gradients over North America and, consequently, increases North American temperature variability. By contrast, the presence of the Tibetan Plateau and the Himalayas on the eastern edge of the Eurasian continent damps temperature variability over most of Eurasia. However, Tibet and the Himalayas also interfere with the downstream development of storms in the North Pacific storm track, and thus damp temperature variability over North America, by approximately as much as the Rockies enhance it. Large-scale orography is also shown to impact the skewness of downstream temperature distributions, as temperatures to the north of the enhanced temperature gradients are more positively skewed while temperatures to the south are more negatively skewed. This effect is most clearly seen in the northwest Pacific, off the east coast of Japan.


2002 ◽  
Vol 80 (12) ◽  
pp. 2207-2217 ◽  
Author(s):  
Daniel E Galazzo ◽  
Selvadurai Dayanandan ◽  
David J Marcogliese ◽  
J Daniel McLaughlin

The systematics of Diplostomum species, common intestinal parasites of piscivorous birds, has long been problematic, owing to phenotypic plasticity and the paucity of morphological features that are often subject to age- and host-induced variation. We sequenced the ITS1–5.8S–ITS2 regions of the rDNA from adult Diplostomum huronense, Diplostomum indistinctum, and Diplostomum baeri obtained from experimentally infected ring-bill gulls (Larus delawarensis) and compared them with partial ITS1 sequences from several species of Diplostomum in GenBank. The three North American species were distinguishable on the basis of ITS sequences. Sequences from D. huronense differed from those of D. indistinctum at 12 sites in ITS1 and 4 sites in ITS2, supporting morphological and morphometric data that indicate the two are distinct species. Sequences of D. huronense and D. indistinctum differed from those of D. baeri at 27 and 24 sites, respectively, in ITS1 and 15 and 12 sites, respectively, in ITS2. Phylogenetic analysis of partial ITS1 sequences revealed that the North American and European species of Diplostomum formed separate groups, with the former being basal to the latter. The results indicated that D. huronense and D. indistinctum from North America are distinct from Diplostomum spathaceum and other similar species from Europe. Furthermore, sequences from specimens identified as D. baeri from North America differed from those of D. baeri from Europe by 3.8% in ITS1 (23 sites). While morphologically similar, the two are not conspecific. Sequences of the North American species have been deposited in GenBank (AY 123042–123044).


1940 ◽  
Vol 18c (9) ◽  
pp. 469-488 ◽  
Author(s):  
Ivan H. Crowell

This study of geographical distribution shows that species of the genus Gymnosporangium are found in the northern hemisphere only and occur most abundantly in the temperate portion. Each of the three major continents contains a distinctive Gymnosporangium flora and, with the exception of three species called the "tricontinental species", species occur naturally in one continent only. The genus contains about 48 species; 33 occur in North America, 15 in Asia and 6 in Europe (including the three tricontinental species in each case). Explanations of the types of geographical distribution of the North American species are given under four categories: (i) species that occupy all potential territory covered by the coincident ranges of their alternate hosts, (ii) species that are confined by the range of their "primary" telial host, (iii) localized species that are confined within a portion of the coincident ranges of their alternate host, and (iv) widely distributed species that are not limited in their range by either alternate host group.


2003 ◽  
Vol 135 (4) ◽  
pp. 549-554 ◽  
Author(s):  
J. Donald Lafontaine ◽  
Kauri Mikkola

AbstractThe North American species previously treated as Xanthia togata (Esper) is shown to be a distinct species and described as new. Illustrations of adults and genitalia of X. togata and Xanthia tatago are provided.


Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1278
Author(s):  
Michael Glenn O’Connor ◽  
Amjad Horani ◽  
Adam J. Shapiro

Primary Ciliary Dyskinesia (PCD) is a rare, under-recognized disease that affects respiratory ciliary function, resulting in chronic oto-sino-pulmonary disease. The PCD clinical phenotype overlaps with other common respiratory conditions and no single diagnostic test detects all forms of PCD. In 2018, PCD experts collaborated with the American Thoracic Society (ATS) to create a clinical diagnostic guideline for patients across North America, specifically considering the local resources and limitations for PCD diagnosis in the United States and Canada. Nasal nitric oxide (nNO) testing is recommended for first-line testing in patients ≥5 years old with a compatible clinical phenotype; however, all low nNO values require confirmation with genetic testing or ciliary electron micrograph (EM) analysis. Furthermore, these guidelines recognize that not all North American patients have access to nNO testing and isolated genetic testing is appropriate in cases with strong clinical PCD phenotypes. For unresolved diagnostic cases, referral to a PCD Foundation accredited center is recommended. The purpose of this narrative review is to provide insight on the North American PCD diagnostic process, to enhance the understanding of and adherence to current guidelines, and to promote collaboration with diagnostic pathways used outside of North America.


2001 ◽  
Vol 49 (5) ◽  
pp. 561 ◽  
Author(s):  
Victor R. Townsend Jr ◽  
Bruce E. Felgenhauer ◽  
Judy F. Grimshaw

We examined the morphology of the genitalia and cuticular scales of eight species of Australian lynx spiders of the genus Oxyopes and compared them with those of representative species from Africa, Asia and North America. Our results indicate that the eight species examined are representative of two distinct species groups of Oxyopes in Australia. The first group consists ofO. amoenus, O. dingo, O. gracilipes, O. molarius, O. rubicundus, and O. variabilis. The evolutionary origin of these spiders is difficult to discern as they share multiple genitalic characters with African and Asian taxa. However, these six species display two characters, leg scales and internal cuticular elements in the opisthosomal scales, that are exhibited by African, but not Asian, taxa. The second group consists of Oxyopes macilentus and O. papuanis. These taxa exhibit many of the same morphological features, exhibited by Asian, but not African, species.


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