Eurasian North American Research Articles

Catalogue of Asplenium septentrionale (L.) (Tracheophyta, Polypodiopsida, Aspleniaseae) specimens deposited in the State Museum of Natural History NASU, Lviv, Ukraine

The detailed analysis of origin of the Asplenium septentrionale (L.) Hoffm. specimens, deposited in the main collection of vascular plants’ herbarium in the SMNH NASU, has been carried out. Asplenium septentrionale (L.) Hoffm. – northern spleenwort – is a perennial fern of the genus Asplenium, the family Aspleniaceae, a Holarctic petrophilous species with a disjunctive Eurasian-North American natural range (Europe, the Caucasus, Central Asia, Western Siberia, Mongolia, Himalayas, Far East, North America). Its localities are confined to petrophilic communities, mainly on granite outcrops devoid of calcium (rock crevices, rocky slopes, landslides, boulders, shady spruce forests, etc.), and the species rises to the upper mountain belt. In Ukraine, this species occurs within the Carpathians, the Crimea, Steppe (Prydniprovska and Azov uplands, Donetsk Ridge) and Forest-Steppe (Volynska and Prydniprovska uplands) zones, Polissya (occasionally in Volynske and Zhytomyrske Polissya). Asplenium septentrionale (L.) Hoffm. has been included into the official lists of regionally rare plants in many regions of Ukraine (Dnipropetrovska, Donetska, Zhytomyrska, Zaporizka, Ivano-Frankivska, Kyivska, Kirovohradska, Luhanska, Rivnenska, Chernivetska provinces and the Autonomous Republic of the Crimea). The main collection of the Herbarium of Vascular Plants in the SMNH NASU contains 26 herbarium specimens of A. septentrionale (L.) Hoffm., all being included into the electronic database "Biodiversity of Ukraine" (http://dc.smnh.org/) and digitized. The geography of the herbarium collections of A. septentrionale (L.) Hoffm., besides the modern territory of Ukraine (Dnipropetrovska (1901), Donetska (1939, 1947, 1965, 1966), Zhytomyrska (1949), Zakarpatska (1948, 1957, 1961, 1969), Ivano-Frankivska (1967), Kirovohradska (1900), Rivnenska (1948) provinces and the Autonomous Republic of the Crimea (1900)), has been represented also by the territories of Poland (1905), Czech Republic, Slovakia, Austria, Romania (1905), Finland (1898) and the Russian Federation (North Ossetia, 1898). In descending order of the number of collected herbarium specimens with the participation of 16 collectors, the following series has been formed: Slobodian M. (3 herbarium specimens), Vainagii I. (2), Voloshchak E. (2), Hanieshyn S. (2), Lazebna A. (2), Malynovskyi K. (2), Zinger M. (2), Berko J. (1), Golde K. (1), Kotov M, Karnaukh E. (1), Markovych V. (1), Melnychuk V. (1), Rheman A. (1), Stoyko S. (1), Finn V. (1), Khrzhyzhanovskyi V., Lazebna A. (1), Shokhin V. (1). The chronology of the herbarium collections covers the period from 1898 to 1969. The earliest specimens (second half of the 19th century) were collected in Finland (V. Shokhin collection) and North Ossetia (V. Markovych collection). This article was written with the support of the National Research Foundation of Ukraine, call 2022.01 «Science for the Recovery of Ukraine in the War and Post-War Periods» the project 2022.01/0013 «Digitization of natural history collections damaged as a result of hostilities and related factors: development of protocols and implementation on the basis of the State Museum of Natural History of the National Academy of Sciences of Ukraine». The contents of this article do not necessarily reflect the views of the National Research Foundation of Ukraine and are the sole responsibility of the State Museum of Natural History, NAS of Ukraine.

Out of Place: Phylogenomics resolves the placement of Eurasian taxa and sheds light on origin of Thermopsideae in North America

The North American Thermopsideae (Fabaceae: Papilionoideae), a monophyletic group comprising the North American endemic genus Baptisia, and the paraphyletic Eurasian–North American disjunct Thermopsis, is nested within the tribe Sophoreae. Previous phylogenetic studies have identified two East Asian taxa within the North American Thermopsideae, suggesting two independent dispersal events between North America–East Asia. More recent studies have also placed a third taxon, Vuralia turcica, an endemic species from Turkey, among the North American Thermopsideae. The presence of three geographically distant Eurasian taxa within a relatively young clade of North American origin is unprecedented among papilionoid legumes, and the biogeographic implications of this observation are not clear. To investigate this matter, 1540 low-copy nuclear genes and complete plastomes were obtained from 36 taxa across the core genistoids, including 26 newly sequenced taxa. Nuclear and plastome based maximum likelihood (ML) and ASTRAL analyses were conducted based on varying degrees of taxon coverage and read mapping consensus threshold values. Additional analyses were performed to estimate divergence times and to reconstruct biogeographic history. The results strongly support a previously undetected Old World clade, presently composed of V. turcica and T. chinensis, which diverged from the ancestor of the North American lineage during the mid to late Miocene. A single and recent North America–East Asia dispersal involving T. lupinoides is reported. Furthermore, the traditional inclusion of the genus Ammopiptanthus among Thermopsideae is not supported, and the monotypic generic status of Vuralia is called into question. A relatively high degree of cytonuclear discordance is reported within each sub-clade of the North American Thermopsideae. This finding is likely attributable to the high degree of interspecific hybridization reported within these groups and raises the need for more rigorous genome-scale testing to better delimit species within each of the reticulating subclades.Subjects: Biodiversity, Biogeography, Evolutionary Studies, Genetics, Plant Science.

Crustal Stresses in the East Arctic Region From New Data on Earthquake Focal Mechanisms

AbstractEast Arctic is a key region for understanding the current geodynamic pattern and lithospheric evolution of the whole Arctic. To close an evident gap in regional seismic data, we calculate source parameters for 103 earthquakes (Mw ≥ 4.2, 1990–2021) and compile a representative uniform data set including source depths, scalar seismic moments, moment magnitudes, and focal mechanisms. On its basis, crustal stresses are estimated within four blocks with the homogeneous stress field. Extension dominates along the Gakkel Ridge and over most of the Laptev Sea shelf. On the continent and east and west of the shelf, it is replaced by compression. The obtained results indicate that the spreading axis of the Gakkel Ridge does not continue to the Laptev Sea shelf and evidence for the Eurasian–North American plate boundary crosses the eastern Laptev Sea shelf and is likely to pass to the Chersky Range through the Yana Bay.

Materials on the synanthropic flora of the city of Khabarovsk

The relevance of the study is due to the fact that city tram tracks, embankments and right of way are specific ecotopes that are subject to significant anthropogenic disturbances and are places of synanthropic plants concentration. We have collected 59 species from 23 families and 49 genera of flowering plants. The family spectrum is dominated by representatives of Asteraceae, the leading family of regional flora. In the generic spectrum, most genera contain one or two species each, which indicates a sufficient floristic capacity of the technogenic ecotope of tram tracks. In terms of life form, perennial herbaceous plants with underground organs survive on the tram tracks, ensuring the constant renewal of plants. Approximately the same number of alien (or adventive) and local (or native) plants have been identified by origin. As expected, alien species are confined to ruderal habitats and are characterized by wide ranges (cosmopolitan, Eurasian-North American, Eurasian types). From local species on tram tracks, plants of open habitats (forest-meadow, meadow, forest edge and slope) find suitable ecological niches.

Ареалогическая структура фауны ржанкообразных птиц в бассейне озера Байкал

An analysis of the structure of local faunas without an arealogical component will be incomplete, since it does not always reflect well the degree of their connection with the fauna of other regions. The purpose of this work is to identify the species composition and conduct an arealogical analysis of the fauna of shorebirds in the Baikal basin. The typological analysis is based on the principles of classification of insect ranges adapted to birds. The geographical distribution of 61 bird species was analyzed, excluding migrant species. They were differentiated according to four arealogical complexes: cosmopolitan, Eurasian-North American, Afro-Eurasian and Eurasian, within which we identified 27 arealogical groups, including 6 longitude groups and 15 latitudinal latitudinal groups. Out of 61 species, 7 species (11.4%) nesting ranges cover more than three continents (cosmopolites), 14 species (23.0%) have Eurasian-North American ranges, 3 species (4.9%) are AfroEurasian (two of them Palearctic), the remaining 37 species (60.7%) nest on the Eurasian continent, of which 14 species live only in Asia. The share of the latter in the fauna of the Charadriiformes of the Baikal basin is more than one quarter (23.0%). In total, the number of species from the Eurasian and Eurasian-North American complexes (83.6% of the fauna of Charadriiformes) clearly prevails over the cosmopolitan and Afro-Eurasian ones. The analysis demonstrates a very complex arealogical structure of the fauna of Charadriiformes in the basin Baikal and, obviously, in the Asian part of the Palearctic as a whole. Most species of shorebirds are inherent in their original range, and there are practically no two species with the same area of distribution. This picture is connected, first of all, with different requirements for habitat conditions in combination with the history of development and formation of their habitats. Charadriiformes, regularly recorded in the Baikal basin, demonstrate a noticeable diversity in the nature of distribution. The fauna is based on Eurasian, and to a lesser extent, Eurasian-North American species. The proportion of cosmopolitan and Afro-Eurasian species is small. According to the latitudinal component, the charter-like species of the region were distributed over natural zones from the Arctic to subtropical zones, and many species adhere to certain climatic zones. Among the nesting species, the presence of temperant and subboreal species is noticeable, which is due to the ecotone position of the region and the diversity of its landscape and ecological conditions

Northern Hemisphere disjunctions in Lactuca (Cichorieae, Asteraceae): independent Eurasia to North America migrations and allopolyploidization

The Lactuca lineage is one of nine lineages in the lettuce subtribe (Cichorieae, Asteraceae) distributed in Europe, Africa, Asia and North America. Within the Lactuca lineage two clades show disjunct Eurasian-North American distributions. One disjunct clade consists of diploids (x = 8) and allotetraploids (x = 17), the former restricted to Eurasia and the latter to North America and the Azores. In contrast, members of the other Eurasian-North American disjunct clade are all diploid (x = 9), like the remainder of the Lactuca lineage (diploid, x = 8 or 9). The aims of the present study were to investigate the migration pathways that led to the disjunct distributions of these two Eurasian-North American clades and the potential progenitors of the allopolyploid taxa. We conducted deep taxon sampling and multi-locus phylogenetic analyses using nuclear ribosomal DNA (ETS and ITS), a low-copy nuclear marker (A44) and five non-coding plastid markers. Divergence time estimations with BEAST and ancestral biogeographic estimations with BioGeoBEARS suggested that both lineages reached North America by the late Miocene. Cloning of the A44 region revealed two sequence copies within allopolyploid individuals that were resolved in divergent clades and this helped to identify potential progenitors. We provide competing hypotheses for the progenitor species and biogeographic pathways that gave rise to the allotetraploid lineage, and we propose a North American origin for the Azorean endemic. Taxonomic conclusions include L. graminifolia var. mexicana being raised to specific rank with the name L. brachyrrhyncha and the alleged endemic L. jamaicensis in fact represents the SE Asian L. indica, introduced to Jamaica.Citation: Jones K. E., Schilling E. E., Dias E. F. & Kilian N. 2018: Northern Hemisphere disjunctions in Lactuca (Cichorieae, Asteraceae): independent Eurasia to North America migrations and allopolyploidization. – Willdenowia 48: 259–284. doi: https://doi.org/10.3372/wi.48.48206Version of record first published online on 24 August 2018 ahead of inclusion in August 2018 issue.

Biogeography and diversification of Holarctic water striders: Cenozoic temperature variation, habitat shifting and multiple intercontinental dispersals

AbstractIt is now rare to find a semi‐aquatic organism group with which to vigorously test whether their diversification model and distribution pattern are closely related to the Cenozoic temperature variation. This hypothesis is explored for water striders of the generaAquariusSchellenberg,GerrisFabricius andLimnoporusStål, which comprise a monophyletic clade with primarily Holarctic distribution. We sample almost 90% of the currently recognizedAquarius,GerrisandLimnoporusspecies. Five DNA fragments from 62 species are used to reconstruct a phylogram. Divergence time is estimated using Bayesian relaxed‐clock method and three fossil calibrations. We investigate diversification dynamics, biogeography and ancestral state reconstruction by using maximum‐likelihood, Bayesian and parsimony approaches. Our results showed that the crown of the three genera originated and underwent an initial diversification in Asia at 72 Ma (HPD: 59–86 Ma) in the Late Cretaceous, subsequently expanding into other regions via dispersal. The Bering Land Bridge was the major migration route between Eurasia and North America but was interrupted before the early Oligocene (34 Ma). Ancestors most likely used lentic habitats, and a minimum of two independent shifts to lotic habitats occurred in the initial diversification. Cenozoic temperature variation regulated the evolutionary history of Holarctic water striders of the generaAquarius,GerrisandLimnoporus. Temperature warming during Stage I (52–66 Ma) was associated with the disappearance of shallow lentic habitats; this phenomenon forced certain lentic lineages to colonize new lotic habitats and promoted the diversification of lineages. Temperature cooling during Stage II (after 34 Ma) was associated with the fragmentation of water habitats of the ‘mixed‐mesophytic’ belt, resulting in the extinction of historical taxa and influencing close lineages that shaped the present disjunct Eurasian–North American distribution.

Co-seismic surface ruptures produced by the 2014 Mw 6.2 Nagano earthquake, along the Itoigawa–Shizuoka tectonic line, central Japan

Field investigations reveal that the Mj 6.8 (Mw 6.2) Nagano (Japan) earthquake of 22 November 2014 produced a 9.3-km-long co-seismic surface rupture zone. The slip occurred on the pre-existing active Kamishiro Fault, which developed along the Itoigawa–Shizuoka tectonic line, and is inferred as the boundary between the Eurasian and North American plates. The surface-rupturing earthquake produced dominant thrusting and subordinate strike-slip displacement. Structures that developed during the co-seismic surface rupture include thrust faults, fault scarps, en-echelon tension cracks, folding structures such as mole tracks and flexural folds, and sand-boils. The surface displacements measured in the field range from several centimeters to 1.5m in the vertical (typically, 0.4–1m), accompanied by a strike-slip component that reached 0.6m along NNE trending ruptures. These observations indicate a thrust-dominated displacement along the seismogenic fault. Our results show that (i) the pre-existing Kamishiro Fault, which strikes NNE–SSW, controlled the spatial distribution of co-seismic surface ruptures and displacements; and (ii) the style and magnitude of thrust displacements indicate that the present-day shortening strain on the Eurasian–North American plate boundary in the study area is released mainly by seismic thrust displacements along the active Kamishiro Fault.

Recurrent short-distance dispersal explains wide distributions of hydrophytic umbellifers (Apiaceae tribe Oenantheae)

Aim Long-distance dispersal (LDD) by migratory birds is often invoked to explain the broad and disjunct distributions of many aquatic plants. Such distributions may also be achieved by recurrent short-distance dispersal (SDD) to adjacent areas and extinctions in connecting areas. To test the relative importance of LDD and SDD in shaping the distributions of hydrophytes, we examined different dispersal models for a clade of hydrophytic umbellifers (Apiaceae tribe Oenantheae). Location Worldwide, with emphasis on Eurasian–North American disjunctions. Methods A dated phylogeny of the group was obtained with Bayesian methods using nrDNA internal transcribed spacer (ITS) and cpDNA rps16–trnK sequences from 100 species and infraspecific taxa of Oenantheae and two outgroup species. Ancestral habits were inferred using maximum likelihood (R package ape). Six connectivity models were compared using a maximum-likelihood-based method (Lagrange), four with symmetrical dispersal rate matrices and two assuming asymmetrical exchanges between Eurasia and North America, with or without spatial and temporal constraints on LDD. Results The age of the crown node of Oenantheae was estimated at 26.3 Ma, and western Europe was reconstructed as its most likely ancestral area. The divergence between Peucedanum sandwicense, an endemic of Hawaii, and its sister Oenanthe occurred 17.2 Ma, pre-dating the emergence of the Hawaiian Islands. Throughout the phylogeny, the hydrophytic habit (including helophytes and amphiphytes) dominated. Of the six connectivity models considered, the model restricting all intracontinental and transoceanic LDDs and assuming an almost unidirectional dispersal from Eurasia to North America received the highest likelihood score. This model was also characterized by the highest dispersal rate. A stratified model assuming a higher probability for dispersals between Eurasia and North America when these continents were connected with land bridges received a lower likelihood score. Main conclusions The results suggest that the broad and often disjunct distribution of Oenantheae hydrophytes is mostly achieved through an increased dispersal rate and recurrent SDD rather than frequent LDD. Our data confirm the asymmetry of the floristic exchange between Eurasia and North America and do not support the increase of this exchange when the continents were connected with land bridges.

Observational responses of stratospheric sudden warming to blocking highs and its feedbacks on the troposphere

The influences of tropospheric blocking high on the stratospheric sudden warming (SSW) and the SSW-induced feedback on the lower atmosphere are analyzed with NCEP (National Center for Environmental Prediction) 2 reanalysis data. Daily mean data from 1979 to 2010 are used to perform statistical and dynamical analyses. According to different distribution features of polar vortex, which can be ascribed to different activities of blocking highs, we have obtained two warming patterns in vortex splitting and displacement patterns. For vortex splitting events, in the Eurasian-North American (ENA) paratype, with disturbances of Atlantic and Aleutian blocking highs, polar vortex is split into two parts that locate at Eurasian and North American continents respectively, while in the Atlantic-East Asian (AEA) paratype, two low-pressure centers derived from the split vortex are situated in the Atlantic and East Asian regions, and two blocking systems occurring in the Urals and North American areas precede these splitting processes. For vortex displacement events, in the Aleutian-Intrusion (AI) paratype, the polar vortex is displaced to the west European and Atlantic areas by the intrusive Aleutian high and this pattern always corresponds to the blocking events occurring in the Pacific basin only. Similarly, the vortex is pushed to the west Eurasian continent by the intrusive North American high-pressure system in the North American-Intrusion (NAI) paratype, which is closely related to the blocking over these areas. The second subject of the research is that whether the anomalous stratospheric signals can be propagated to the lower atmosphere, which is depended on the intensity, duration and position of the disturbed vortex. According to our case studies, geopotential height anomalies can be propagated to the troposphere in strong SSW years, taking about 10–15 d for the decrease from 10 to 500 hPa, leading to apparent variations in the geopotential height and temperature fields.

Carbonate-rich melt infiltration in peridotite xenoliths from the Eurasian–North American modern plate boundary (Chersky Range, Yakutia)

A suite of mainly spinel peridotite and subordinate pyroxenite xenoliths and megacrysts were studied in detail, enabling us to characterize upper mantle conditions and processes beneath the modern North American–Eurasian continental plate boundary. The samples were collected from 37-Ma-old basanites cropping out in the Main Collision Belt of the Chersky Range, Yakutia Republic (Russian Far East). The spinel lherzolites reflect a mantle sequence, equilibrated at temperatures of 890–1,025 °C at pressures of 1.1–2 GPa, with melt extraction estimated to be around 2–6 %. The spinel harzburgites are characterized by lower P–T equilibration conditions and estimated melt extraction up to 12 %. Minor cryptic metasomatic processes are recorded in the clinopyroxene trace elements, revealing that percolating hydrous fluid-rich melts and basaltic melts affected the peridotites. One of the lherzolites preserves a unique melt droplet with primary dolomite in perfect phase contact with Na-rich aluminosilicate glass and sodalite. On the basis of the well-constrained P–T frame of the xenolith suite, as well as the rigorously documented melt extraction and metasomatic history of this upper mantle section, we discuss how a carbonated silicate melt infiltrated the lherzolite at depth and differentiated into an immiscible carbonate and silicate liquid shortly before the xenolith was transported to the surface by the host basalt. Decreasing temperatures triggered crystallization of primary dolomite from the carbonate melt fraction and sodalite as well as quenched glass from the Na-rich aluminosilicate melt fraction. Rapid entrainment and transport to the Earth’s surface prevented decarbonatization processes as well as reaction phenomena with the host lherzolite, preserving this exceptional snapshot of upper mantle carbonatization and liquid immiscibility.

Magmatism at the Eurasian–North American modern plate boundary: Constraints from alkaline volcanism in the Chersky Belt (Yakutia)

The Chersky seismic belt (NE-Russia) forms the modern plate boundary of the Eurasian−North American continental plate. The geodynamic evolution of this continent−continent setting is highly complex and remains a matter of debate, as the extent and influence of the Mid-Arctic Ocean spreading center on the North Asian continent since the Eocene remains unclear. The progression from a tensional stress regime to a modern day transpressional one in the Chersky seismic belt, makes the understanding even more complicated. The alkaline volcanism that has erupted along the Chersky range from Eocene through to the Recent can provide constraints on the geodynamic evolution of this continental boundary, however, the source and petrogenetic evolution of these volcanic rocks and their initiating mechanisms are poorly understood.We studied basanites of the central Chersky belt, which are thought to represent the first alkaline volcanic activity in the area, after initial opening of the Arctic Ocean basin. We present mineral and bulk rock geochemical data as well as Sr–Nd–Pb–Hf isotopes of the alkaline suite of rocks combined with new precise K–Ar and 40Ar/39Ar dating, and discuss an integrated tectono-magmatic model for the Chersky belt. Our findings show that the basanites were generated from a homogeneous asthenospheric mantle reservoir with an EM-1 isotopic flavor, under relatively ‘dry’ conditions at segregation depths around 110km and temperatures of ~1500°C. Trace element and isotope systematics combined with mantle potential temperature estimates offer no confirmation of magmatism related to subduction or plume activity. Mineral geochemical and petrographical observations together with bulk geochemical evidence indicate a rapid ascent of melts and high cooling rates after emplacement in the continental crust. Our preferred model is that volcanism was triggered by extension and thinning of the lithosphere combined with adiabatic upwelling of the underlying mantle at 37Ma. This suggests that at that time, rift tectonics in the Mid-Arctic Ocean most likely had also affected the North-Asian continent, causing volcanic activity in the Chersky belt, before the regional geodynamic regime changed from a tensional to compressional. Our conclusions contribute not only to the understanding of volcanism in the Chersky seismic belt (NE-Russia) but also to general aspects of plate dynamics between the Eurasian and North American continent.

Late Cretaceous–Cenozoic deformation of northeast Asia

The plate tectonic paradigm implies rigid plates and narrow plate boundaries. In contrast, diffuse plate boundaries are common both in the oceans and continents [R.G. Gordon, Annu. Rev. Earth Planet. Sci. 26 (1998) 615–642], and their history is difficult to constrain, especially in remote, tectonically complex areas such as northeast Asia [M.E. Chapman, S.C. Solomon, J. Geophys. Res. 81 (1976) 921–930]. Here we show how extensive North Atlantic marine magnetic [R. Macnab et al., EOS 76 (1995) 449, 458] and gravity data [D.T. Sandwell, W.H.F. Smith, J. Geophys. Res. 102 (1997) 10039–10054] can be used to unravel, with tight confidence limits, successive periods of deformation over 80 million years, along the diffuse continental Eurasian–North American plate boundary. A period of compression in the Late Cretaceous (14 mm/yr in the Laptev Sea to 20 mm/yr in Kamchatka) led to thrusting in the Verkhoyansk Mountains, and was followed by extension from 68 to 40 Ma when ∼400 km of extension was accommodated by the formation of a series of grabens, including the Moma Rift system. Since 40 Ma, time-varying compression and transpression along the Moma Rift system created strike-slip faults, thrusts and folds at rates up to 6.3 mm/yr. In the Laptev Sea region, 600 km of extension from latest Late Cretaceous to present created the Laptev Sea and Lena Rift systems. The deformation predicted by our model fits most geological features formed in the Laptev Sea and central northeast Asia during Late Cretaceous–Cenozoic times. The most recent deformation (Late Miocene–Pliocene) is not very well constrained since our model lacks data younger than 11 Ma. The deformation that occurred in Kamchatka reflects a complex tectonic setting and our model’s predictions are only tentative.

Identification of breakpoints in intergenotypic recombinants of HIV type 1 by bootscanning.

Identification of breakpoints in intergenotypic recombinants of HIV type 1 by bootscanning.

The Genus Seligeria in New Zealand

The genus Seligeria in New Zealand is represented by two species- S. cardotii R. Br. and S. diminuta (R. Br.) Dixon. The former is closely related to S. pusilla in the subgenus Seligeria; the latter to S. recurvata in the subgenus Cyrtoseligeria. The close relationships of both of these endemic species to broadly distributed Northern Hemisphere species and the presence of additional apotypic character states in the New Zealand taxa suggest long-distance dispersal and subsequent evolutionary divergence. Seligeria cardotii is distinguished from S. diminuta by pale coloration, linear vegetative leaves, straight setae, and hemi- spheric-obconic capsules with short exothecial cells; it is probably not uncommon in areas of exposed calcareous rocks on both islands. Seligeria diminuta, known from three collections, is rare and distinguished from the former species by dark coloration, subulate-ovate vegetative leaves, markedly cygneous setae and oblong- ovate capsules with longer exothecial cells. The genera Seligeria and Blindia, in addition to several, small segregate genera, com- prise the family Seligeriaceae. This haplolepideous family, with its unique peristome struc- ture, probably deserves recognition in its own order or suborder. The peristome, consisting of a single layer composed of two fused rings of cell plates, can be distinguished from all other haplolepideous peristome types by having a very thin, smooth, inner layer and an outer layer with thickened transverse walls (Edwards 1979). In some specimens the re- sorption of the outermost wall of the outer layer of plates is not complete, resulting in an additional peristomial layer being present at the base of a few teeth. There have been 19 species recognized in the genus, 17 by Vitt (1976), and two addi- tional European species recently described by Schauer (1964). Of these, 13 occur in North America (one endemic) and 16 in Europe (four endemic) while two species are found in New Zealand. Both of these are restricted to New Zealand in distribution; however, each of these species has close phyletic relationships with circumboreal species of the Northern Hemisphere. Seligeria cardotii R. Br. is a member of the type subgenus, most closely related to the Eurasian-North American S. pusilla (Hedw.) B.S.G. and to the western North American endemic S. careyana Vitt & Schof. The second species of the genus found in New Zealand, S. diminuta (R. Br.) Dixon, can be placed in the subgenus Cyr- toseligeria Vitt, and is closely related to Seligeria recurvata (Hedw.) B.S.G., a species sporadically distributed in the Northern Hemisphere, but most common in eastern Europe and eastern North America. Assuming the phyletic dendrogram presented by Vitt (1976) is reasonably correct, then both New Zealand endemics possess apotypic character states that align them with distinct subgenera. Within each of these subgenera, both of the New Zealand species contain 007-2745/83/106-113$0.95/0