The smut fungi of Greenland

Abstract The first taxonomic treatment of the smut fungi in Greenland is provided. A total of 43 species in 11 genera are treated and illustrated by photographs of sori, microphotographs of spores in LM and SEM, and distribution maps. Two species, Anthracoidea pseudofoetidae and Urocystis tothii, are recorded as new from North America. Thirteen species, Anthracoidea altera, A. capillaris, A. limosa, A. liroi, A. pseudofoetidae, A. scirpoideae, A. turfosa, Microbotryum lagerheimii, M. stellariae, Schizonella elynae, Stegocintractia luzulae, Urocystis fischeri, and U. tothii, are reported for the first time from Greenland. Three new fungus-host combinations, Anthracoidea capillaris on Carex boecheriana, Anthracoidea pseudofoetidae on Carex maritima, and Urocystis tothii on Juncus biglumis, are given. Five plant species are reported as new hosts of smut fungi in Greenland, namely, Carex nigra for Anthracoidea heterospora, C. canescens for Anthracoidea karii, C. fuliginosa subsp. misandra for Anthracoidea misandrae, C. maritima for Orphanomyces arcticus, and C. fuliginosa subsp. misandra for Schizonella melanogramma. Three species, Microbotryum violaceum s. str. (recorded as ‘Ustilago violacea’), Urocystis anemones, and U. junci, which were previously reported from Greenland, are considered wrongly identified. Additional distribution records are given for 12 species from Greenland: Anthracoidea bigelowii, A. caricis, A. elynae, A. lindebergiae, A. misandrae, A. nardinae, A. rupestris, A. scirpi, Schizonella melanogramma, Stegocintractia hyperborea, Urocystis agropyri, and U. sorosporioides. The most numerous distribution groups are the following: circumpolar–alpine and Arctic–alpine species – 14; circumboreal–polar species – 10; and circumpolar and Arctic species – 6. The most widely distributed smut fungi in Greenland were Anthracoidea bigelowii, A. elynae, Microbotryum bistortarum, and M. vinosum. Most species were found in the High Arctic zone (29 species), while from the Low Arctic zone and the Subarctic zone, 26 and 19 species were known, respectively. Ten species, Anthracoidea bigelowii, A. capillaris, A. elynae, Microbotryum bistortarum, M. koenigiae, M. pustulatum, M. silenes-acaulis, M. vinosum, Schizonella elynae, and Urocystis sorosporioides, were recorded from all three zones. Only plants belonging to six families, Cyperaceae, Poaceae, Juncaceae, Ranunculaceae, Caryophyllaceae, and Polygonaceae, out of a total of 55 in the flora of Greenland, hosted smut fungi. Cyperaceae was the plant family with most host species (23). Carex was the genus with the highest number of host species (22). The total number of the host plants (45 species) was 8.5 % out of a total of 532 vascular plants in the flora of Greenland. A new combination in Carex, C. macroprophylla subsp. subfilifolia, is proposed for Kobresia filifolia subsp. subfilifolia.

government to the International Court in Haag, which in 1933 declared a continued Danish-Greenlandic sovereignty of the area. Due to the dispute, the area became the focus for new visitors and expeditions for the two governments to mark their presence. In this way, international politics boosted the knowledge of smut fungi in Greenland. Of special importance for the investigation of smut fungi was a group headed by Norwegian botanist Asbjørn Hagen, accompanied by J. Vaage, B. Bjørlykke, S. Aandstad, P.F. Scholander, andJ. Devold. In the period 1929-1933, the group made 166 collections of smut fungi, including a few found during perusal of herbarium holdings. Details of these collections were published by Hagen in 1941 and as 12 species (actually, 21 species based on modern taxonomy of Anthracoidea). Most notable were their records of Haradaea nivalis, Anthracoidea caricis s. lat., Schizonella melanogramma, Stegocintractia hyperborea, and Urocystis triseti. Urocystis tothii was also collected by Hagen, but only identified in the present study. A collection by Bjørlykke was later identified by D.B.O. Savile as Anthracoidea verrucosa.
A few other notable records are from the same period. The Danish lichenologist P. Gelting found Anthracoidea altera (1946), which was identified in the current study. In this period, the Danish pharmacist J. Lind contributed a number of papers on micromycetes from Arctic areas, and in one of these he published Anthracoidea scirpi, one of the species also collected by Vahl, but identified by Rostrup under the collective name Ustilago caricis.
After World War II, there was significant development in science and technology, universities grew and new, modern methods were applied to the study of smut fungi. The invention of the scanning electron microscope allowed detailed study of the spore wall ornamentation. At the same time, a change in the view of species concepts spread among taxonomists, and a number of Scandinavian mycologists started an intense study of the smut fungi on Cyperaceae. The Finnish mycologist J.I. Liro (1872Liro ( -1943 had for many years before the war collected smuts and other parasitic fungi and gathered them in his Mycotheca Fennica. His studies pioneered and stimulated other Scandinavian mycologists (J.-A. Nannfeldt, B. Lindeberg, I. Kukkonen) and the Canadian (D.B.O. Savile) to collect and study smut fungi. They published comprehensive papers on the smut fungi of northern Europe and Canada.
As a part of these studies, Greenlandic material was often used for comparison with material from other countries. Savile, Nannfeldt, Kukkonen, and Jørstad revised Greenlandic specimens and in the period 1957-1979, nine new species for Greenland were reported, mainly due to the splitting of Anthracoidea caricis Lindeberg 1957, 1965;Kukkonen 1963Kukkonen , 1964Kukkonen , 1965Kukkonen , 1969Nannfeldt 1977Nannfeldt , 1979.
Most recently, Henning Knudsen, Torbjørn Borgen, and Steen A. Elborne collected basidiomycetes in Greenland in 2016-2018 for a forthcoming funga of Arctic and Alpine basidiomycetes. They collected in three areas: (i) Kangerlussuaq-Sisimiut, (ii) Constable Pynt on Jameson Land, and (iii) Narsarsuaq-Kangilinnguit-Kobbe fjord. Their collections included 50 specimens of smuts, containing 16 species. Two were new to Greenland, but were also found when unidentified collections by J. Vahl and T. Laessøe were re-examined.
Two authors of the present treatment (T.T.D. & C.M.D.) went through the herbarium of vascular Greenlandic plants in Copenhagen, holding approximately 200 000 sheets. They repeated Rostrup's method and examined the plants known to be hosts for smuts. The result was surprisingly good, considering that the infected parts of the plants were very small and therefore unnoticed by the collecting botanist. One hundred and twenty-one collections from 26 species were found, including many inconspicuous species difficult to see unless their occurrence was suspected. Among them, seven species were new to Greenland. They also found another eight species among the unidentified collections made by previous collectors.

Vegetation and main habitats
Greenland is the world's largest island stretching 2500 km from Cape Farewell (59°45'N) in the south to the northernmost land in the world, Cape Morris Jesup (83°39'N). From West (Cape Alexander 73°3'W) there is 1000 km to Nordostrundingen (11°19'W) in the East. This is at the same time the easternmost point of the North American continent.
In spite of this huge area, the climate is rather uniform, strongly influenced by the northern position, the vast interior cover of Inland Ice, and influence from drift ice from the Arctic Ocean.
Most of Greenland belongs to the Arctic zone, defined by the average temperature for the warmest month being < 10 °C. This vast part is divided into Low Arctic and High Arctic, following 70°N passing through central Disko Island in the West to Jameson Land in the East. The distance between the West coast and the East coast of Greenland is separated by 200-1000 km of permanent ice, which should be considered in any comparison between the two sides. Another important point is the drift ice, making the Eastern side of Greenland colder than the Western side, and consequently only inhabited in two settlements, Ammassalik in the southern part and Ittoqqoormiut in the central part of the coast, separated by 800 km! Alnus crispa (Aiton) Pursh forms restricted shrubs in the SW part of Greenland and continues to a much larger scale in Canada. Several other shrubs occur over most of Greenland. Salix is represented by five species of which S. uva-ursi Pursh has the same distribution as A. crispa, whereas S. arctophila Cockerell is distributed over most of western Greenland. S. glauca subsp. callicarpaea (Trautv.) Böch., S. herbacea L., and S. arctica Pall. have a much wider, circumpolar distribution. Betula glandulosa Michx. forms extensive, 0.25-1 m high shrubs in SW Greenland,being gradually replaced by B. nana L. continuing up to 75°N. In the western part of South Greenland, the deep fjords have a subarctic climate at the bottom. They have characteristic, well-developed copses or very locally even a kind of forest of Betula pubescens Ehrh. s. lat. In protected valleys, the trees may reach 8-9 m in height and the trunks can be ca 30 cm in diam., but this type of copse is restricted to a few km 2 . The species itself reaches ca 63°N.
Apart from the climate, the soil has an important impact on the distribution of plants and fungi in Greenland. The Greenland geology is complicated. A large part has a bedrock of acidic granite, but locally and especially in central Greenland, a broad band of calcareous rocks and soil is found on both the Western and Eastern side around 70°N (Disko Island and Jameson Land). In this area a number of calcicolous species are present.
A phytogeographical division of Greenland was proposed by Feilberg (1984), Bay (1992), Fredskild (1996) and Bay (in prep.). Each of these deals with a specific part of Greenland, viz. South, North, West, and East. The division is mainly based on the distribution of vascular plants and placed where the largest number of northern or southern distributional limits occur. South Greenland ranges from Cape Farewell, 59°45'N to 62°20'N, which is just south of the large glacier Frederikshåb Isblink. South of this area many plants have their northern limit in Greenland. The flora province is divided into six subzones by oceanity versus continentality and Low Arctic versus Subarctic. Feilberg (1984) concluded from his data that Nathorst's (1890) view of southern Greenland as a province more related to the East than to the West as seen by the occurring plants was correct. In South Greenland flora province 346 species of vascular plants occur, the richest area being around Narsarsuaq with 309 species. West Greenland ranges from 62°20'N to 79°30'N, with a subdivision from 74°N to 79°30'N, the Northwest Floristic Province. On the eastern side, there is a similar Northeast Floristic Province, a part of East Greenland, from 79°30'N to 74°N. In the West Greenland flora province 390 species are found, being 379 species up to 74°N (Fredskild 1996) and another 11 up to 79°30'N. An important distributional line goes through the middle of Disko Island where 62 species have their northern limit, and 18 species have their southern limit. This is by far the most important floristic boundary in western Greenland and marks the limit between High Arctic and Low Arctic.
The phytogeographical province North Greenland ranges from the northernmost point in Greenland,Cape Morris Jesup,83°39'N south to 79°30'N. In western Greenland, the boundary is the Humboldt Glacier, in eastern Greenland Lambert Land. Only 121 vascular plants are known from this province. East Greenland stretches from 79°30'N and south to 62°20'N. An analysis of this region is in preparation (Bay pers. comm.).
The Greenland plant habitats are often difficult to recognize and characterize. The habitats gradually merge into one another or are mixed with each other.
Herbslopes are formed on south-exposed slopes with a good supply of water. They are often conspicuous in the landscape containing plants with large flowers and low shrubs. Typical species are Rhodiola rosea L., Angelica archangelica subsp. norvegica, For this study, Greenland is divided into three regions (Fig. 1A), following a delimitation applied for the Panarctic Flora project (PAF - Elven et al. 2018); the only exception being the location of the boundary between North and East Greenland: • North Greenland (as part of Ellesmere Land -Northern Greenland Region) includes the northernmost parts of Greenland from Melville Bay in the west (ca 75°25'N) to Nordostrundingen in the east (at 81°26'N). The boundary between North Greenland and East Greenland chosen here follows the SW-NE-trending watershed in Crown Prince Christian Land (after Ostenfeld 1926: 21;Higgins 2010), while the boundary proposed in PAF lies north of the glaciers between Germania Land and Lambert Land. • West Greenland includes western and southernmost Greenland to Lindenow Fjord (ca 60°30'N) in SE Greenland. • East Greenland -from Nordostrundingen to Lindenow Fjord.
The examined and/or recorded specimens of fungi are arranged from north to south (first from the western side to Lindenow Fjord in the southeast, then from the eastern part).

Materials and methods
This study is based on examination of specimens from the following dried reference collections: C -Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark; DAOM -Canadian National Mycological Herbarium, Ottawa, Canada; E -Royal Botanic Garden Edinburgh, Edinburgh, U.K.; GZU -Karl-Franzens-Universität Graz, Graz, Austria; K(M) -Kew Fungarium, Royal Botanic Gardens, Kew, U.K.; O -Botanical Museum, University of Oslo, Oslo, Norway; S -Swedish Museum of Natural History, Stockholm, Sweden; U -Utrecht, now transferred to L (Naturalis, Leiden, the Netherlands), but curated as a separate collection; WSP -Washington State University, Pullman, Washington, U.S.A.
Dried specimens were examined using a stereo zoom microscope (for observation of sori), light microscope (LM), and scanning electron microscope (SEM). For LM observations and measurements, spores were mounted in lactoglycerol solution (w : la : gl = 1 : 1 : 2) on glass slides, gently heated to boiling point to rehydrate the spores, and then cooled. The measurements of spores are given as min-max (extreme values) (mean ± 1 standard deviation). For SEM, spores were attached to specimen holders by double-sided adhesive tape and coated with platinum or gold in an ion sputter. The surface structure of spores was observed and photographed at 10 kV accelerating voltage using a JEOL JSM 6610-LV scanning electron microscope (Natural History Museum Vienna) and Hitachi SU3500 (National Museum of Natural History, Paris). The type of spore ornamentation and height of ornamenting elements (warts, spines, striae, muri) were analyzed and measured in SEM. The height of ornamenting elements was additionally measured in Olympus BX-51 (in magnification ×2000, through an image analysis software). In the case of verruculose or verrucose spore ornamentation, the type of ornamentation was defined in accordance with Denchev et al. (2013: 10). The descriptions below are based entirely on the specimens examined. The shapes of spores are arranged in descending order of frequency.
Spore size ranges of the Canadian Anthracoidea species were discussed by Savile (1952) and assigned by him to one of the following groups: (i) small-sized spores, 13-21(-23) × 9-17(-20) µm, (ii) medium-sized spores, 15-25(-27) × 10-21 µm, and (iii) large-sized, 18-33 × 13-28 µm. In this case, spore width is of very little use. Spore length of the known 111 species of Anthracoidea was analyzed by us and the following modification of Savile's system for spore length ranges of species in this genus is suggested herein (Table 1). Table 1. Spore length ranges of the species in Anthracoidea.
Throughout the taxonomic section, Anthracoidea is abbreviated as 'A.', Carex as 'C.', Cintractia as 'Ci.', Tuburcinia as 'Tub.', Urocystis as 'Ur.', and Ustilago as 'U.'. The regions of Greenland are abbreviated as follows: NG = North Greenland, WG = West Greenland, and EG = East Greenland. On the plates with illustrations, scale bars on macrophotographs represent 0.5 cm, those of LM and SEM microphotographs 10 µm and 5 µm, respectively, and of maps 500 km.

Taxonomic treatment
Key to the genera of smut fungi in Greenland, based on host plant families Sori in and around ovaries of cyperaceous plants (in the cases of Carex -scattered in female spikes or in female flowers of mixed spikes), usually partly hidden by the glumes; as globose, subglobose, broadly ellipsoidal or ovoid, rarely ellipsoidal, black, hard bodies; composed of the remainder of the nut in the center and a spore mass around it (spore formation on the outer surface of the nut); originally covered by a thin, white, grayish or silvery peridium of fungal cells, hyphae, and fragments of host cells, which ruptures exposing the spore mass. Spore mass initially firmly agglutinated, later powdery or semi-agglutinated on the surface, less often mature sori agglutinated on the surface and breaking into small, irregular pieces; composed only of teliospores, sterile cells absent. Spores formed singly, usually flattened, in plane view more or less regular in outline (orbicular, suborbicular or broadly elliptical) or more or less irregular, relatively large (compared to the spores of other genera of smut fungi); surrounded by a gelatinous sheath that breaks down at maturity (sometimes mature spores with remnants of that gelatinous sheath). Spore wall unevenly or evenly thickened; rarely with pale, thinner-walled polar regions; with or without protuberances, often with internal swellings and/or light-refractive areas, usually ornamented with warts, rarely punctate or smooth, few species with coarse (up to 2 µm high), irregular ornaments, apically flattened and slightly enlarged. Spore germination results in a two-celled aerial basidium forming one or more basidiospores on each cell; basidiospores globose, subglobose, ovoid or cylindrical. Anamorph present in some species. Host-parasite interaction (after Vánky 2013) by intracellular hyphae, coated by an electron-opaque matrix. Mature septa (after Vánky 2013) poreless. Initially, the sori are covered by a thin membrane. Mature teliospores are liberated and dispersed by wind after the membrane ruptures. At an early stage of plant flowering, spores germinate, produce basidiospores, and infect flowers. The infection is local, floral (confined to individual flowers). Hyphae are localized in the ovaries and walls of single nuts. The spores are produced on the outer nut surface (Kukkonen 1963;Kukkonen and Vatanen 1968;Vánky 2002). Infected flowers do not form seeds as the ovaries are destroyed.
Based on the type of spore germination, the genus Anthracoidea is divided into two subgenera. Anthracoidea subgen. Anthracoidea is characterized by small to mediumsized spores (13-25 µm long) and globose, subglobose or ovoid basidiospores, up to 30 µm long, several produced per basidial cell. Anthracoidea subgen. Proceres Kukkonen is characterized by medium to large spores (22-37 µm long) and cylindrical basidiospores, 40-90 µm long, only one produced per basidial cell (Kukkonen 1963;Vánky 2011). Unfortunately, the type of spore germination is known only for some of the species, making it difficult to refer all of the species to a subgenus.
The genus Anthracoidea comprises 111 species. It is a cosmopolitan genus, but more widely distributed in Temperate, Subarctic, and Arctic regions of the Northern Hemisphere.
The species of Anthracoidea are restricted to host plants belonging to the same or closely related sections of Carex (Vánky 1979).
Specimens examined or recorded. Comments -Dietrich (1967) recognized two subspecies of Carex fuliginosa, distributed in the alpine and Arctic regions of Europe, respectively. The specimens from mountains of Central and Southeast Europe are treated as belonging to subsp. fuliginosa, while those from the Arctic region are referred to subsp. misandra (= C. misandra). This infraspecific scheme is accepted in many recent sources (e.g., Flora Europaea, Chater 1980;Euro+Med PlantBase, Jiménez-Mejías and Luceño 2011;Panarctic Flora, Elven et al. 2018) and is applied herein. In the Flora of North America treatment (Ball and Mastrogiuseppe 2002), however, Carex misandra is considered to be conspecific with C. fuliginosa.
Carex fuliginosa subsp. misandra is a circumpolar taxon, distributed in northernmost Fennoscandia (restricted), Svalbard, Franz Joseph Land, Russian Arctic, Siberia, Russian Far East, Alaska, Canada (reaching southwards in the mountains of western U.S.A.), and Greenland (Hultén and Fries 1986: 517;Bay 1992;Fredskild 1996;Egorova 1999;Elven et al. 2018). Although the host plant is considered as frequent in the Arctic, Anthracoidea altera is known only from a few localities: Finland (Mt. Saana, Nannfeldt 1979), Svalbard (Spitsbergen -Lomfjorden, Hagen 1950bIsfjorden, Kukkonen 1963, as 'A. misandrae'), and Canada (Baffin Island, Frobisher Bay, Kukkonen 1963, as 'A. misandrae';Nannfeldt 1979), and it seems that this smut fungus is a rare species. Its northernmost collection is reported from Spitsbergen (Lom-fjorden), at ca 79°23'N. Anthracoidea altera is an Arctic species that is recorded here for the first time from Greenland. It is worth noting that A. altera is not found on Carex fuliginosa subsp. fuliginosa, while A. misandrae is known to infect both subspecies of C. fuliginosa.
Comments -Anthracoidea bigelowii is one of the most widespread species of this genus in Greenland. In this study, many infected specimens of Carex bigelowii from Greenland were seen but only some of them were unambiguously assigned to A. bigelowii due to the following main problems: (i) the taxonomy of the C. bigelowii complex is not sufficiently solved, (ii) the sori in some collections are too young, and (iii) the number of Anthracoidea species on sedges in the C. bigelowii complex seems to be higher than currently known.
The Carex bigelowii complex includes a group of taxa distributed throughout the Arctic and in the mountains of the Temperate zone (Hultén and Fries 1986: 474;Holub 1968). Chater (1980: 320) considered Carex bigelowii as 'an extremely variable species whose infraspecific taxonomy is confused ... by the occurrence of numerous hybrids and by the fact that published work on it has never taken full account of the variation over the whole range'. Brief overviews of the studies of this complex of sedges and lists with published synonyms are given in Brooker et al. (2001) and Schönswetter et al. (2008). In Flora Europaea (Chater op. c.), a single species, C. bigelowii, with four subspecies were accepted: (i) subsp. bigelowii in North Europe (also in Greenland and northeastern North America); (ii) subsp. rigida W. Schultze-Motel in Central and northwestern Europe, and western Fennoscandia; (iii) subsp. arctisibirica (Jurtzev) Á. Löve & D. Löve in northern Russia (and Siberia); and (iv) subsp. ensifolia (Turcz. ex Gorodkov) Holub in the southern Ural (and Siberia).
In the Flora of North America treatment (Standley et al. 2002), two subspecies were distinguished within C. bigelowii in North America: subsp. bigelowii, distributed in Central Canada, North American Atlantic Region, Greenland, and North Europe, and subsp. lugens (Holm) T.V. Egorova with an amphi-Beringian distribution.
Based on results from molecular investigations of Schönswetter et al. (2008), three subspecies are recognized within C. bigelowii in Panarctic Flora ): (i) subsp. bigelowii -a North American-amphi-Atlantic taxon (distributed in northeastern North America, Greenland, Iceland, and northern Scandinavia); (ii) subsp. rigida -a European (central and northwestern)-amphi-Atlantic taxon (distributed in mountains of Central Europe, and in Norway, British Isles, Iceland, and Greenland); and (iii) subsp. ensifolia -a European (northeastern)-Asian (northern)-amphi-Beringian taxon (distributed in Svalbard, northeastern Europe, northern Asia, and northwestern North America). This complex of species is in need of additional molecular and morphological studies.

3(3)
Hosts and distribution within the studied area -On Cyperaceae: Carex sect. Chlorostachyae Meinsh.: Carex boecheriana -West Greenland; C. capillaris -West Greenland (Fig. 4G Canada, Greenland. Comments -In this study, Carex capillaris (the type host plant of Anthracoidea capillaris) is considered in its broad sense. In its broad circumscription, this sedge is a circumboreal-polar species, distributed in the Arctic but characteristic also for the boreal zone and mountains of Central and South Europe and North America (Hultén and Fries 1986: 512;Egorova 1999;Elven et al. 2018). Carex capillaris has been variously interpreted in the botanical literature. In the Flora of North America treatment (Ball 2002c), infraspecific taxa were not recognized within this species. In some recent treatments, however, C. capillaris is considered as a highly polymorphic species at a circumpolar scale (Saarela et al. 2013;Alsos et al. 2018;Elven et al. 2018), and accepted as a core species in a species aggregate, including C. capillaris -with two subspecies: subsp. capillaris (var. capillaris and var. elongata Olney ex Fernald) and subsp. fuscidula (V.I. Krecz. ex T.V. Egorova) Á. Löve & D. Löve), and C. krausei Boeckeler . A third species, C. boecheriana (known from Greenland and Ellesmere Island), is also referred to this species aggregate, but some authors (e.g. Elven et al. 2018) consider it synonymous with C. krausei. Whether the morphological differences are sufficient to warrant its recognition as a distinct species is yet to be satisfactorily resolved. All five taxa within the C. capillaris aggr. are listed as occurring in Greenland, because of which we prefer to consider the host plant of the infected Greenlandic specimens in its broad sense. The case of C. boecheriana is an exception, as the identification of the cited specimens is confirmed by P.W. Ball.
Anthracoidea capillaris on Carex capillaris s. lat. has been previously reported from Canada, North Europe, the Alps, the Carpathians, and Kurile Islands (Nannfeldt 1979;Denchev and Minter 2010;Denchev et al. 2013). In Canada, it is known from Yukon, Northwest Territories, Nunavut, British Columbia, Manitoba, Quebec, and Newfoundland and Labrador (Kukkonen 1963;Parmelee 1983Parmelee , 1988. Anthracoidea capillaris is recorded here for the first time from Greenland, on two host plants: Carex boecheriana and C. capillaris. The Greenlandic specimens show the typical features of A. capillaris (cfr Nannfeldt 1979;Vánky 2011;Denchev et al. 2013).
Comments -Anthracoidea caricis is the type species of its genus. Initially, this species (as 'Ci. caricis') was generally considered to have a wide host range, including many species of Carex (comp. Fischer 1953;Zundel 1953). Later, it was recognized as a collective species (including Ci. irregularis Liro) that was parasitic on sedges in two sections, Acrocystis and Digitatae (Kukkonen 1963). Cintractia irregularis was recognized by Boidol and Poelt (1963) as a distinct species and transferred to Anthracoidea. Nannfeldt (1979) reduced the host range of A. caricis to sedges of section Acrocystis. Vánky (1994) and Guo (2000) proposed Carex halleriana (section Hallerianae) and some species of C. sect. Digitatae to be added to the list of hosts of Anthracoidea caricis. The current status of Anthracoidea on these sedges, as well as on C. vanheurckii, was discussed by Denchev et al. (2013) in the comments given to A. caricis and A. caryophylleae, respectively. The smut fungi, currently referred to as 'A. caricis', clearly form a species complex that requires further study. In the present treatment, A. caricis is considered in a broad sense.
Carex deflexa is a North American species. The Greenlandic plants belong to var. deflexa, distributed in Canada, northeastern U.S.A., and Greenland (Crins and Rettig 2002). The Cordilleran var. boottii (from mountain regions of the western North America) is also reported as a host of A. caricis (Kukkonen 1963).
In its strict sense, Anthracoidea caricis is a Eurasiatic species with a disjunct distribution, mainly in the territory of temperate Eurasia. It is found in Europe, Iran, Mongolia, and East Asia (Denchev et al. 2013). The circumscription of this species is not satisfactorily resolved. In the present treatment, focused only on the smut fungi of Greenland, A. caricis is considered in a broad sense, as a circumboreal species. The taxonomic status of A. caricis complex will be discussed elsewhere.

EG,
Comments -The circumscription of the genus Carex was recently expanded to include all species of the genera Cymophyllus, Kobresia, Schoenoxiphium, andUncinia (Global Carex Group 2015, 2016). The new taxonomic scheme of Carex will reflect on the taxonomy of the Anthracoidea species on hosts of the former genus Kobresia, but the consequences thereof will not be discussed here since the present study is focused only on the smut fungi of Greenland, where only two Anthracoidea species on 'Kobresia' are distributed and they can be morphologically distinguished.
Comments -Anthracoidea heterospora has a bipolar distribution. It is a widely distributed smut fungus (mainly in North Europe and northern North America), reported on many species in the section Phacocystis. The following sedges can be listed as principal hosts: Carex acuta, C. aquatilis, C. cespitosa, C. nigra (type host), C. lyngbyei, and C. trinervis. In North America, A. heterospora is known from numerous localities in Alaska, Yukon, Northwest Territories, British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, Labrador, and Newfoundland (Nannfeldt and Lindeberg 1965;Parmelee 1983Parmelee , 1988. Three specimens of A. heterospora, on hybrids of Carex bigelowii, have been recorded from Greenland (Nannfeldt and Lindeberg 1965: 195, as A. heterospora on 'C. bigelowii × ?'). These specimens were revised by us but only one of them was accepted as correctly identified. The other two specimens -East Greenland Hagen 1947, as 'Ci. caricis' on 'Carex rigida Good.') -cannot be reliably referred to A. heterospora due to the presence of slightly higher spore wall ornamentation than is typical for A. heterospora; higher value of the minimum spore length, (15-)16 µm versus (12-)13 µm for A. heterospora; and slightly higher values of the mean spore length and width, (18.2 ± 1.0 × 16.7 ± 1.0 µm), than is typical for A. heterospora.
The description given here is based on the specimen of A. heterospora on C. nigra. Carex nigra belongs to the European floristic element. This sedge occurs also in Siberia, North Africa, and South Greenland. In East Canada and northeastern U.S.A., it is an alien species (Egorova 1999). Carex nigra is recorded here for the first time as a host of A. heterospora in Greenland.
Comments -Anthracoidea karii, considered in a broad sense, is a circumborealpolar species with a very wide host range. It is reported to infect 19 sedges, belonging to four sections of Carex subg. Vignea (Nannfeldt 1977;Vánky 2011;Denchev et al. 2013), among which the following can be considered as principal hosts: in sect. Glareosae -C. brunnescens and C. lachenalii, in sect. Physoglochin -C. dioica and C. parallela, and in sect. Stellulatae -C. echinata.
For the purpose of this treatment, many Greenlandic specimens of infected sedges of the host range of A. karii were studied, but only that on C. brunnescens and C. canescens were accepted as belonging to A. karii. The Anthracoidea specimens on other sedges do not fit well the characters of A. karii on its type host, C. brunnescens, observed by us in comparative specimens from Europe. The excluded specimens (see the list below) possess spores with similar shape, sizes, and wall thickness but variable in height of the spore wall ornamentation, and number and conspicuousness of the in-ternal swellings. For this reason, the fungus in the current study is accepted in a strict sense. The description given here is based on specimens of A. karii on C. brunnescens. Molecular data are needed for clarification of the taxonomic status of the Anthracoidea species on Carex glareosa, C. gynocrates, C. lachenalii, and C. paralella.
For the time being, the following Anthracoidea specimens cannot be reliably referred to A. karii: On  (Nannfeldt 1977) and C. ursina (Fischer 1953, as 'Ci. caricis';Nannfeldt 1977) but no voucher specimens were cited or are known to exist.
In Canada, Anthracoidea limosa is reported from Yukon, Northwest Territories, Nunavut, British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, Labrador, Newfoundland, New Brunswick, and Prince Edward Island; found on Carex limosa, C. magellanica subsp. irrigua, C. pluriflora, C. rariflora, and hybrids between some of them (Savile 1952;Kukkonen 1963;Parmelee 1983Parmelee , 1988. Anthracoidea limosa is a circumboreal-polar species. Further studies must be carried out in order to determine whether or not the eastern Asian and North American specimens belong to distinct species (Denchev et al. 2013).

9(9)
Hosts and distribution within the studied area -On Cyperaceae: Carex (the Simpliciuscula clade): Carex simpliciuscula -West Greenland (Fig. 10G Earlier reports from Greenland: Kukkonen (1961, as 'Ci. lindebergiae', 1963. Comments -The host plants of Anthracoidea lindebergiae were previously recognized as members of the genus Kobresia. As already noted in the comments to Anthracoidea elynae, the circumscription of the genus Carex was recently expanded to include all species of the genera Cymophyllus, Kobresia, Schoenoxiphium, and Uncinia (Global Carex Group 2015, 2016) that will reflect on the taxonomy of the Anthracoidea species on hosts, previously recognized as members of Kobresia, as a distinct genus.
In the Flora of North America treatment (Ball 2002a), Kobresia simpliciuscula (a principal host of A. lindebergiae) is considered in a broad sense, as a circumpolar-alpine species, without recognition of distinct infraspecific taxa. In Egorova's taxonomic revision of Kobresia in Russia (1983), three subspecies were distinguished: subsp. simpliciuscula, accepted as a European taxon; K. simpliciuscula subsp. subholarctica T.V. Egorova, described there as distributed in Arctic Russia, Siberia, Russian Far East, and North America; and K. simpliciuscula subsp. subfilifolia (T.V. Egorova et al.) T.V. Egorova, as endemic to the northeastern Russian Arctic and Subarctic. Currently, two subspecies are recognized within Carex simpliciuscula: subsp. simpliciuscula, a mainland European taxon, not distributed in the Arctic, and subsp. subholarctica, an Asian (northeastern)amphi-Beringian-North American (northern)-amphi-Atlantic taxon, distributed in Siberia, Russian Far East, Alaska, Canada, Greenland, and Svalbard (Saarela et al. 2017;Alsos et al. 2018;Elven et al. 2018); while subsp. subfilifolia is accepted within Kobresia filifolia, as an Asian (northeastern)-amphi-Beringian taxon . As the species of Kobresia are now recognized in Carex (Global Carex Group 2015) and the correct name for K. filifolia in Carex is C. macroprophylla (Y.C. Yang) S.R. Zhang (op. c.), a new combination for subsp. subfilifolia is necessary to be proposed: The host plant of Anthracoidea lindebergiae in Greenland should be accepted as belonging to Carex simpliciuscula subsp. subholarctica (T.V. Egorova) Saarela.
Specimens examined or recorded.
General distribution. North Europe: Svalbard, Iceland, Faeroes, UK, Norway, Sweden, Finland, Denmark, Estonia, North and Arctic Russia. Asia: East Siberia, Arctic Russia, Russian Far East. North America: Arctic and Subarctic Canada.
Comments -Anthracoidea liroi is a circumpolar species. It attacks many sedges in Carex sect. Phacocystis, but, as pointed out in Nannfeldt (1979: 28), designation of principal hosts for this smut fungus would be meaningless for the following reasons. A significant number of the specimens of A. liroi, stored in the collections, are on hybrids (e.g., more than half of the Swedish specimens, studied by Nannfeldt and Lindeberg), and this material often is insufficient for an exact identification of the host (cfr Nannfeldt and Lindeberg 1965: 206). In assessing the significance of the hosts, the ecological requirements of this smut fungus should be taken into account. Anthracoidea liroi is a northern (without records outside the northern countries), montane, and maritime species, while A. heterospora (on sedges in the same section) follows on the whole the distribution of its hosts, except for the far North (Nannfeldt and Lindeberg 1965;Nannfeldt 1979).
On Carex fuliginosa subsp. misandra (a circumpolar taxon), A. misandrae has been previously recorded from Fennoscandia, Alaska, and Canada (British Columbia, Nunavut) (Linder 1947, as 'Ci. caricis';Savile 1952, as 'Cintractia limosa var. minor';Kukkonen 1963;Nannfeldt 1979). There are three records of a smut fungus on this sedge from Svalbard (Spitsbergen) (Gjaerum 1991). For the first time, it was mentioned by Lind (1928, as 'Ci. caricis on Carex misandra'), but it is necessary his voucher specimen (if any) to be re-identified. Afterwards, it was reported by Hagen (1950b, as 'Ci. caricis on Carex misandra'), but considering Hagen's spore measurements, this record should be referred rather to Anthracoidea altera than to A. misandrae. A third specimen from Spitsbergen was published by Kukkonen (1963), as a paratype of A. misandrae, but later it was assigned to A. altera (Nannfeldt 1979). Carex fuliginosa subsp. misandra is reported here as a new host of A. misandrae for Greenland.
As noted, Anthracoidea altera is not found on Carex fuliginosa subsp. fuliginosa, while A. misandrae is known to infect both subspecies of C. fuliginosa. Carex fuliginosa subsp. fuliginosa is an alpine, Central and South European plant (Hultén and Fries 1986: 517;Egorova 1999) that is recorded as infected by A. misandrae from Austria, Slovakia, and Romania (Vánky 1985a;Zwetko and Blanz 2004).
Carex stenantha var. taisetsuensis is reported as infected by A. misandrae from the northern Kurile Islands (Paramushir - Govorova 1987Govorova , 1990Denchev et al. 2013). There are no molecular data for this sedge. Because of this reason, we continue to treat it as a member of section Aulocystis and a host of A. misandrae.
Comments -Kukkonen (1963) described Anthracoidea elynae var. nardinae to accommodate a smut on Carex nardina. In its protologue, this sedge was designated as a single host. In a comment to Anthracoidea externa in the same treatment, however, Kukkonen assigned two specimens of a smut fungus on Carex elynoides also to A. elynae var. nardinae. Carex elynoides has in previous times been considered as belonging to Carex sect. Filifoliae (cfr Mastrogiuseppe 2002). For this reason, in the world monograph of Vánky (2011), the hosts of A. nardinae, Carex nardina and C. elynoides, are referred to different sections -Nardinae and Filifoliae, respectively. However, results of recent molecular studies (cfr Global Carex Group 2016) show that section Filifoliae should be merged with section Nardinae. That is why, in the current treatment, all hosts of A. nardinae are referred to Carex sect. Nardinae. The smut fungi on Carex nardina complex and C. elynoides deserve further study.
The taxonomic status of the taxa in the Carex nardina complex has been a subject of much debate. Some authors (e.g., Egorova 1966Egorova , 1999 accepted Carex nardina and C. hepburnii as distinct species, while other considered them as a single variable species (e.g., Chater 1980;Murray 2002;Aiken et al. 2007;Sawtell 2012;Saarela et al. 2017). In Panarctic Flora  and Flora of Svalbard (Alsos et al. 2018), however, two subspecies are recognized within Carex nardina: subsp. nardina, an amphi-Atlantic taxon, distributed in the mountains of Arctic Norway and Sweden, Iceland, (?) Greenland, and (?) Canada, and subsp. hepburnii, an amphi-Beringian-North American-amphi-Atlantic taxon, known from the Russian northeastern Arctic, Alaska, Canada, U.S.A. (the Cordilleras), Greenland, and Svalbard. Unfortunately, Greenland falls within the area with the highest uncertainty regarding the infraspecific delimitation of this sedge: 'doubts about Greenland and Canada are about whether both subspecies are present' . That is why, in the current treatment a broader circumscription for the Greenlandic specimens of Carex nardina is applied.

14(14)
Hosts and distribution within the studied area -On Cyperaceae: Carex sect. Comments -Anthracoidea pseudofoetidae is reported here for the first time from Greenland and North America and Carex maritima is a new host for this smut fungus.
Anthracoidea pseudofoetidae was previously known only on C. pseudofoetida, from the type collection (Guo 2006). Both sedges are members of Carex sect. Foetidae but C. pseudofoetida is a Central Asiatic species, with distribution restricted to mountains in Central Asia, while C. maritima is a widespread species, with a bipolar distribution (in South America from Ecuador to Argentina), being a circumpolar-alpine species in the Northern Hemisphere -distributed there in Alaska, Canada, Greenland, and northern Eurasia, as well as in alpine regions of Europe and Central Asia (Hultén and Fries 1986: 436;Egorova 1999;Reznicek 2002;Villaverde et al. 2015;Elven et al. 2018;Govaerts 2018).
The two localities recorded here significantly extend the geographic range of A. pseudofoetidae and reveal an unexpected disjunct distribution. Of course, this disjunction may reflect insufficient sampling -many parasitic fungi in the Arctic are superficially known and it may be expected that additional localities of A. pseudofoetidae will be found -but considering that, at least, one of its hosts is a widespread species, it seems that this smut fungus is a very rare species.
The type locality of A. pseudofoetidae is in Tibet, at 5200 m; while the Greenlandic localities are in the High Arctic, at ca 73°44-47'N. This smut fungus is an Arctic-alpine species with restricted distribution and perfect adaptation to extreme conditions: low temperatures and a short growing season of the host plants.
Specimens examined or recorded.
Specimens examined or recorded. Comments -Anthracoidea scirpoideae infects only one sedge, Carex scirpoidea, belonging to Carex sect. Scirpinae -a section with three species, distributed primarily in North America (Dunlop 2002). Four subspecies are recognized in the C. scirpoidea complex: (i) subsp. scirpoidea is the most widely ranging taxon in section Scirpinae, distributed from East Siberia, Russian Far East, Alaska, Yukon, and British Columbia, across northern North America, east to Newfoundland, northern New England, and Greenland, and in the mountains in western U.S.A., as well as with a disjunct population in Norway (an Asian (northeastern)-amphi-Beringian-North American (northern)-amphi-Atlantic (western) taxon; Elven et al. 2018); (ii) subsp. convoluta occurs only along the shores of Lake Huron; (iii) subsp. stenochlaena is distributed in mountains from Alaska and Yukon to northwestern U.S.A.; and (iii) subsp. pseudoscirpoidea that is distributed at higher altitudes (3300-3900 m) in the mountains in southern British Columbia and western U.S.A. (Dunlop and Crow 1999).
Comments -Anthracoidea turfosa is an amphi-Atlantic-European (northern) species, distributed in the eastern boreal part of North America, Greenland, and the northern temperate and boreal parts of Europe. In Canada, this smut fungus is known on Carex gynocrates from Quebec (Savile 1952, as 'Ci. limosa var. limosa'), and on Carex exilis from Quebec, Labrador, and Nova Scotia (Savile 1952, as 'Ci. pratensis';Nannfeldt 1977;Parmelee 1983). Anthracoidea turfosa and A. karii (a species with smaller spores) have common hosts belonging to sections Physoglochin (including hybrids), Stellulatae, and Glareosae, or to intersectional hybrids. For this reason, some published records (especially, some from North America) need re-examination (see also Nannfeldt 1977: 368-372).
Anthracoidea turfosa is reported here for the first time from Greenland.
Specimens examined or recorded.
Comments -Anthracoidea verrucosa infects North American sedges in the sections Ovales and Phaestoglochin. This smut fungus has been purposefully studied by Savile (1952) and Nannfeldt (1977Nannfeldt ( , 1979) but in fact, information about its hosts and distribution continues to be insufficient. Based on available records (Hagen 1947;Savile 1952;Nannfeldt and Lindeberg 1957;Nannfeldt 1977;Farr and Rossman 2019), A. verrucosa is distributed on several closely related sedges in Alaska and mountains in British Columbia (Mt. Brent, Mt. Apex) and western U.S.A. (in Wyoming, Utah, Colorado, and Lessen Volcanic National Park in California), and on C. macloviana var. macloviana in East Greenland. Since C. macloviana is a widespread species, it is still unclear whether A. verrucosa is a smut fungus with a large disjunction in the distribution or this disjunction reflects insufficient sampling.
Carex macloviana var. macloviana is a sedge with bipolar distribution (in South America from Peru to Tierra del Fuego and Falkland Islands), being an amphi-Pacific-Cordilleran-North American (northern)-amphi-Atlantic taxon in the Northern Hemisphere -distributed there in Russian Far East, Hawaiian Islands, Alaska, Subarctic Canada, western U.S.A., Greenland, Iceland, and northern Fennoscandia (Hultén and Fries 1986: 466;Egorova 1999;Mastrogiuseppe et al. 2002;Elven et al. 2018). Surprisingly, on this sedge Anthracoidea verrucosa is known only from East Greenland (Hagen 1947).
Based on the cited records, A. verrucosa is a North American (northern)-Cordilleran species.

Anthracoidea sp.
Allescher and Hennings (1897: 40) reported a collection of Cintractia caricis on Carex incurva made in 1892 in West Greenland. The name Carex incurva is reduced to a synonym of C. maritima (Govaerts 2018). Two smut fungi are known to infect flowers of C. maritima: Anthracoidea pseudofoetidae and Planetella lironis. In this treatment, both species are reported for the first time from Greenland.

Earlier reports from Greenland: Allescher and Hennings
Comments -Entyloma microsporum var. pygmaeum is recorded only from the type locality. No voucher specimen is known to exist. Sori in ovules of plants belonging to Caryophyllaceae, filling the capsules with a purplish or dark reddish brown spore mass; peridium and columella lacking, sterile cells absent. Spores single; spore wall reticulate, rarely incompletely reticulate.

Microbotryum
Specimens examined or recorded.

Earlier reports from Greenland: Denchev et al. (2019).
Comments -The anther-smut fungi of Microbotryum on hosts in the Caryophyllaceae cause formation of teliospores instead of pollen in the anthers of bisexual flowers. When female flowers of dioecious species (e.g., in the cases of Silene latifolia and S. dioica) are infected, suppression of stamen development does not occur, and development of spore-bearing anthers is induced (Kazama et al. 2005). The most widely studied anthericolous smuts are those in the anthers of Silene. It is a group of seventeen, highly host specific fungi. Regarding the sorus morphology, they may be divided into two groups: (i) species causing typical anther infection, with sori restricted to the anthers (four species, M. arcticum, M. lagerheimii, M. silenes-acaulis, and M. stellariae, in Greenland); and (ii) species causing atypical infection, with sori usually formed not only in the anthers but also in the filaments, and causing formation of swollen and deformed flowers, completely filled with spore mass (one species, M. savilei, potentially occurring in Greenland) (Denchev et al. 2019).
Microbotryum arcticum on Silene uralensis subsp. arctica was recently described from the High Arctic of Greenland and the Canadian Arctic Archipelago (Denchev et al. 2019). Four specimens from North Greenland (including the holotype) and a specimen from East Greenland are listed in the protologue, as examined. Other six specimens from East Greenland -reported by Hagen (1947) as 'U. violacea' on 'Melandrium apetalum', but not found in the herbarium in Oslo -were also considered as belonging to M. arcticum (Denchev et al. 2019).
The taxonomic status of the host plant was briefly discussed in Denchev et al. (2019). Silene uralensis (sect. Physolychnis) is a very variable species complex (Morton 2005) with not completely clarified specific and infraspecific delimitation. In Bocquet's treatment of Silene sect. Physolychnis (1967), four subspecies have been recognized within Silene uralensis: uralensis, apetala, arctica, and porsildii (a tetraploid plant). The populations in Svalbard have been treated as belonging to an endemic subspecies, arctica, while those in Scandinavia and Bering Sea islands have been recognized as subsp. apetala (S. wahlbergella Chowdhuri). The remaining populations have been referred to as subsp. uralensis (with a northern circumpolar distribution). Hultén (1968) accepted two subspecies: Melandrium apetalum subsp. arcticum, mapped by him as having a circumpolar distribution, and subsp. apetalum from Scandinavia. In Flora Nordica (Jonsell 2001), however, the Fennoscandian plants were treated as a distinct species, S. wahlbergella, and accordingly, only the Arctic plants from North America and Asia were related to S. uralensis. In the Silene treatment for Flora of North America (Morton 2005), three subspecies were recognized within the S. uralensis complex: subsp. uralensis, as a widespread, Arctic circumpolar entity; subsp. porsildii, distributed in Yukon, Alaska, and Arctic Asia; and subsp. ogilviensis from the Canadian Low Arctic. Of these, only subsp. uralensis was given as represented in Greenland and the eastern Canadian Arctic Archipelago. Elven et al. (2018) disagreed with Bocquet's view that subsp. arctica was restricted to Svalbard, and recognized three subspecies of S. uralensis: subsp. uralensis, with a circumpolar distribution (NE Europe, Arctic Asia, Bering Sea islands, Alaska, Canada, and W & S Greenland); subsp. arctica, also with a circumpo-lar distribution (Arctic Far East of Russia, northernmost Alaska and Canada, Greenland, and Svalbard); and subsp. ogilviensis.
Thus, according to the taxonomic scheme of Elven et al. (2018), two subspecies of S. uralensis are represented in Greenland. Silene uralensis subsp. uralensis is characterized by a calyx that is not strongly inflated and usually longer than broad, and petals slightly emerging from the calyx, less so than in subsp. arctica ). The calyx of S. uralensis subsp. arctica is inflated, in flower stage ca. 1.5 times as long as broad (Alsos et al. 2018). In Greenland, there is an overlap in the ranges of the northern subsp. arctica and more southern subsp. uralensis at 70-71°N but there are no obvious transitional plants ). In the first half of the last century, the High Arctic entity in Greenland, arctica, was referred to as 'Melandrium apetalum' (e.g., Kruuse 1905;Ostenfeld and Lundager 1910;Hartz and Kruuse 1911;Ostenfeld 1926;Porsild, M. 1926). The southernmost localities of subsp. arctica are at 69°42'N in West Greenland (Porsild, M. 1926) and 69°30'N in East Greenland (Kruuse 1905) while northwards it reaches 83°06'N (Maguire 1950). Considering that subsp. uralensis is distributed only on the west and south coasts of Greenland, the host plant of the Microbotryum specimens recorded by Hagen (1947) on 'Melandrium apetalum' from East Greenland (at 73°29'-74°32'N) were accepted as belonging to subsp. arctica (Denchev et al. 2019).
Specimens examined or recorded.

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Hosts and distribution within the studied area -On Caryophyllaceae: Silene acaulis -West and East Greenland (Fig. 26G).  Comments -Silene acaulis is a circumpolar-alpine species, with a large Siberian disjunction in the distribution (Hultén and Fries 1986: 791). In the Flora of North America treatment (Morton 2005), it was considered as a variable species but without recognition of infraspecific taxa. In Hultén and Fries (1986) and in Panarctic Flora , however, two subspecies are recognized within S. acaulis: subsp. acaulis, a North American (northeastern)-amphi-Atlantic-European-Asian (northwestern) taxon, and subsp. subacaulescens (F.N. Williams) Hultén, an amphi-Beringian-Cordilleran taxon (distributed in the Russian Far East, Aleutian Islands, and the Cordillera -extending down from Alaska to Arizona and New Mexico). In Europe, S. acaulis is a polar-alpine species with occurrences in the Arctic, Subarctic, Ural, and the higher mountains.
Comments -Both the host plant and the smut fungus are circumpolar-alpine species (Hultén and Fries 1986: 657).
Specimens examined or recorded.
Comments -The spore germination of this smut fungus is insufficiently studied. Durán and Safeeulla (1968: 241) succeeded to germinate spores of 'Cintractia arctica' but only in water (not in nutrient media). The germination reported by them resulted in formation of long, sinuous, septate 'promycelia with lateral outgrowths ' (op. cit.,Figs 27,28).
Both Carex lachenalii and C. maritima (regarding its distribution in the Northern Hemisphere; see the comments to Anthracoidea pseudofoetidae) are circumpolar-alpine species. The smut fungus, Orphanomyces arcticus, is also an Arctic-alpine species. It is a rarely collected species, distributed as follows: in Europe in Iceland and Fennoscandia, and in the Alps and the Pyrenees; in Asia in the Kamchatka Peninsula and mountains in Mongolia and China; and in North America in the eastern Canadian Arctic Archipelago and Greenland, and in mountains in western U.S.A. (Wyoming, Utah, Colorado) (Rostrup 1886(Rostrup , 1904Blytt 1896;Lind 1934;Liro 1938;Lindeberg 1959;Jørstad 1963;Savile and Parmelee 1964;Jørstad and Gjaerum 1966;Schmiedeknecht and Puncag 1966;Durán and Safeeulla 1968;Braun 1999;Guo 2000;Kruse et al. 2013;Farr and Rossman 2019).
Although Orphanomyces arcticus had been reported from Greenland by Rostrup (1904), this record was not included in the monographic treatment of the North American smut fungi of . The only known record of Orphanomyces arcticus from Greenland is based on an infected plant, identified as 'Carex sp.', collected by C. Kruuse during the Danish expedition to East Greenland in 1900. The plant collections from this expedition are listed in Kruuse (1905), and Carex lachenalii (as 'C. lagopina') is the only sedge, collected along Hurry Inlet (or with a locality labeled more generally as 'Scoresby Sund'), that is currently known as a host of Orphanomyces arcticus. That is why, in this treatment the host plant of the smut fungus recorded by Rostrup (1904) is referred to Carex lachenalii.
Hosts and distribution within the studied area -On Cyperaceae: Carex maritima -West Greenland (Fig. 30F).
Specimens examined or recorded.
Comments -As noted in the comments to Anthracoidea pseudofoetidae, Carex maritima is a widespread species, with bipolar distribution (in South America from Ecuador to Argentina), being a circumpolar-alpine species in the Northern Hemisphere -distributed there in Alaska, Canada, Greenland, and northern Eurasia, as well as in alpine regions of Europe and Central Asia. On this sedge, Planetella lironis is known only from the type locality in eastern Canada and a locality in West Greenland (Savile 1951;Denchev and Denchev 2018). It is noteworthy that P. lironis is not reported from North Europe and the alpine regions of Central Europe, which are among the best studied regions in the world for smut fungi, i.e. its absence there is not due to inadequate studies.
The second host, Carex sabulosa, has a very restricted distribution in North America. It is known from only 14 localities in Yukon and one in Alaska (Murray 2002;Baikal Sedge Recovery Team 2012). Carex sabulosa is also known from East Siberia, Kazakhstan, and North Mongolia (Egorova 1999). Planetella lironis is found at most localities of C. sabulosa in Yukon (Baikal Sedge Recovery Team 2012), but has never been found in Asia. Elven et al. (2018) recognize two subspecies within C. sabulosa: subsp. sabulosa (widespread in Siberia) and subsp. leiophylla (Mack.) A.E. Porsild (in Yukon and one in Alaska).
Planetella lironis is a remarkable example of a smut fungus with restricted distribution although its principal host is a widespread plant species (Denchev and Denchev 2018). Because the locality in the Yukon Territory is non-Arctic, the distribution of this smut fungus may be defined as northern North American. Sori in leaves of Cyperaceae as black, short or long, pustulate streaks with agglutinated to powdery spore mass. Spores originally in pairs, arising by internal division of a mother cell, later may be separated into single spores. In S. cocconii spores born in pairs are agglutinated into balls. Spore germination of Ustilago-type. Host-parasite interaction by intracellular hyphae, coated by an electron-opaque matrix. Mature septa poreless (Vánky 2013).
Specimens examined or recorded.
Comments -Carex myosuroides is a circumpolar-alpine species (Hultén and Fries 1986: 423;Elven et al. 2018), distributed in Eurasia and North America. There are two smut fungi on this host plant: Anthracoidea elynae and Schizonella elynae. Whereas A. elynae is a widespread smut fungus, S. elynae seems to be uncommon all over the area of its host.
In the keys to the relevant Schizonella species, both spore color and length are usually used for distinguishing S. elynae from S. melanogramma. In the current case, however, only one specimen of S. melanogramma from Greenland (on C. fuliginosa subsp. misandra) was available to the authors and unfortunately, its sori were too young. Because of this reason, the spore sizes in the description are smaller than the typical ones for S. melanogramma, and spore length is not used in the key to this species.
Carex fuliginosa subsp. misandra is a new host for this smut fungus in Greenland. Infection systemic. Sori on plants in the Juncaceae, in all spikelets or around pedunculi of an infected inflorescence, forming a black, agglutinated spore mass with a powdery surface. Young sori covered by a fungal peridium, sterile stroma lacking. Spores single, pigmented (brown), ornamented, without appendages. Host-parasite interaction by intracellular hyphae, coated by an electron-opaque matrix. Mature septa poreless (Vánky 2013).
Key to the relevant Stegocintractia species  , usually with two thinner and lighter stripe-like areas on the opposite flattened sides of the spores, moderately verruculoseechinulate, ornaments up to 0.5(-0.6) µm in height, spore profile affected. In SEM ornaments densely spaced, isolated or confluent in small groups; with an elongated or sometimes rounded concave areas of the flattened sides. Hosts and distribution within the studied area -On Juncaceae: Luzula confusa, L. nivalis -North and East Greenland (Fig. 33G).

EG,
A third host, Luzula arcuata, is listed in Vánky (2011), but it is erroneously added to the host plants on the base of Lindeberg's (1959: 119) treatment of Stegocintractia hyperborea (as 'Ustilago hyperborea') in Sweden where L. confusa (that had been already recorded from Sweden by Liro 1938, andSelander 1950) is accepted as a synonym of L. arcuata.
Stegocintractia hyperborea is a rarely reported smut fungus. Surprisingly, the highest number of its localities are in Greenland. On the basis of available information, the distribution pattern of S. hyperborea is an amphi-Atlantic (western)-European (northern) & Asian (northeastern Arctic) species, with one Atlantic-northern European part area and another Far East Arctic part area. Since both host plants are circumpolar species, it is still unclear whether S. hyperborea is a fungus with remarkably large disjunctions in the distribution (in the Canadian Arctic and Russian Arctic) or these disjunctions reflect insufficient sampling. In both cases, S. hyperborea is a good example of a smut fungus that does not follow the distribution of its hosts.  Infection systemic. Sori in all spikelets of an infected plant, filling the basal part of the perianth and surrounding the spikelet axis, more or less enclosed by the perianth segments, initially covered by a thin peridium which soon flakes away exposing an initially agglutinated, later powdery spore mass. Spores slightly flattened, in plane view suborbicular, orbicular or broadly elliptical, sometimes slightly irregular or ovate, in plane view (19.5-)20.5-28.5(-30) × (18.5-)19.5-25(-26) (25.0 ± 1.9 × 22.3 ± 1.4) µm (n/ 2 = 200), medium to dark reddish brown; wall unevenly thickened, (1.6-)1.8-3.2(-3.5) µm thick (a faint, 0.7-1.3 µm thick inner layer may be observed in some spores), often with a thinner, slightly paler rounded area of 8-13 µm diam, foveolate. In SEM spore wall shallow-foveolate, foveoles rugulose on the bottom, wall densely punctate to minutely verruculose between foveoles. Spore germination (after Piepenbring 2000: 324) results in ramified hyphae.
Specimens examined or recorded.
On Comments -Stegocintractia luzulae is reported here for the first time from Greenland. It was found on Luzula multiflora, a circumboreal-polar species (in its broad circumscription).
Stegocintractia luzulae is a circumboreal species, found on thirteen species of Luzula. It is an easily overlooked smut fungus, with records mainly from Fennoscandia and Central Europe (Liro 1938;Lindeberg 1959;Jørstad 1963;Vánky 1985a;Zogg 1986;Scholz and Scholz 1988;Zwetko and Blanz 2004;Riegler-Hager 2007;Klenke and Scholler 2015). From North America, S. luzulae has been previously recorded only from Alaska (on Luzula multiflora subsp. frigida, Savile 1957) Infection systemic or local. Sori on host plants in the Poaceae, most commonly in the ovaries, which fill with a semi-agglutinated or powdery spore mass intermixed with sterile cells. In some species, the sori are formed on leaves and culms, as streaks. Exceptionally, the sori appear as swellings on the culms or cover the surface of the leaves, or form witches' brooms. Peridium and columella lacking. Spores single, medium to large sized, usually ornamented (reticulate, cerebriform, verrucose, tuberculate or with cylindrical projections), rarely smooth, often encased in a hyaline gelatinous sheath. Sterile cells usually present between the spores, solitary, variously shaped, smooth but also weakly or evidently ornamented, hyaline or slightly pigmented, naked or sheathed. Spore germination by means of an aseptate basidium (holobasidium), bearing terminal basidiospores which often conjugate in situ, giving rise to infection hyphae, blastospores and ballistospores (secondary sporidia), or basidiospores numerous, acicular, giving rise to infection hyphae without conjugation. Host-parasite interaction by intercellular hyphae; interaction apparatus is lacking. Septal pore is a dolipore traversed by two membranous plates, pore caps lacking (after Vánky 2013).  Durán and Fischer 1961: 46).
Comments -In Greenland, Tilletia cerebrina is only known from Thule, with a single gathering from 1919 on Deschampsia brevifolia. Some authors (e.g. Kawano 1966;Tzvelev 1976;Chiapella and Probatova 2003;Chiapella 2016) considered Deschampsia brevifolia as part of D. cespitosa complex, with a rank of subspecies. In this case, the correct name is D. cespitosa subsp. septentrionalis Chiapella, because the combination proposed by Tsvelev, D. cespitosa subsp. brevifolia (1974), is an illegitimate name, as a later homonym of D. cespitosa var. brevifolia Griseb. (1852). Other authors (e.g. Aiken et al. 2007;Saarela et al. 2017;Elven et al. 2018) suggested this plant to be treated as a distinct species.
In North America, U. fischeri is a rarely recorded smut fungus, reported only from Alberta, Manitoba (Bisby et al. 1938;, and western U.S.A. (Wyoming, Colorado, and California -Fischer 1953;Herb. BPI records).
Urocystis fischeri is reported here for the first time from Greenland. This record is very interesting as it is the northernmost locality of this fungus (at 72°43'N) and its only locality in the High Arctic. ( pared with a specimen of U. junci on Juncus filiformis from Bulgaria (SOMF 1975), and with an isotype of U. tothii (Vánky,Ustilag. Exsicc.,no. 194). It was found that the Greenlandic specimen possesses spore balls composed of 1-5(-9) spores, corresponding to U. tothii. Thus, Urocystis junci must be removed from the list of the smut fungi in Greenland, as a wrongly identified species. Urocystis tothii is recorded here as a new species for Greenland and North America. Juncus biglumis is a new host of U. tothii. It is worth noting that the specimens from U.S.A. on Juncus balticus are identified by  as U. junci, although their spore balls are described as composed of one to several spores, mostly 2-4, that does not match this species. For this reason, a comparative molecular and morphological study of Urocystis on Juncus in U.S.A. and Canada is required.
For illustration of spores, see Denchev (1995 Savile and Parmelee (1964), Denchev (1995). Comments -Pleuropogon sabinei is a circumpolar species while Ustilentyloma pleuropogonis is known only from the North American High Arctic -the Canadian Arctic Archipelago and North Greenland (Savile and Parmelee 1964;Denchev 1995). In the mycological collections, there are only three specimens of this smut fungus, kept at DAOM and studied by Savile (in Savile and Parmelee 1964) and Denchev (1995). Our efforts to find an infected plant among the specimens of Pleuropogon sabinei in the Greenland Herbarium in Copenhagen were unsuccessful. Since all three specimens of Ustilentyloma pleuropogonis are very scant, the only specimen measured by Denchev (1995) was one of the paratypes, DAOM 92913.
The Canadian and Greenlandic finds are located in the Ellesmere Land -Northern Greenland floristic region (Bay 1992;Elven et al. 2018). The Greenlandic locality on Peary Land, at 82°10'N, is one of the northernmost localities known for a smut fungus.
Comments -The holotype was seen by us. There is no smut fungus in this specimen.

Geographic ranges and distribution of the smut fungi in Greenland
As observed by Nannfeldt (1979: 6), the maximum geographic range of a parasitic fungus is the range of its host (or the combined ranges of its hosts). Parasitic fungi usually have a smaller range than the host plant because of the ecological demands of the fungi and their dispersal efficiency. Assessment of geographic ranges depends on the accumulation of distribution records. The level of completeness of that information varies among regions. In the discussed case, it is a real problem since the number of records from Greenland, Arctic Canada, Alaska, Siberia, and Arctic Russia is limited. The current assessment is based on existing collections and available literature records of smut fungi from Greenland. Because all smut fungi are associated with plants, the distribution patterns applied here correspond to the phytogeographical patterns of the Arctic plants, as they are circumscribed in Elven et al. (2018): circumpolar -"more or less continuous throughout the Arctic and often the northernmost boreal parts of Eurasia and North America (including Greenland) but excluding the temperate mountain ranges"; circumpolar-alpine -"circumpolar and with occurrences in one or more temperate mountain ranges south of the boreal zone"; circumboreal -"more or less continuous throughout the boreal and often the temperate parts of Eurasia and North America (sometimes including southern Greenland)"; circumboreal-polar -"a combined circumboreal and circumpolar pattern, from boreal/temperate to Arctic". The species referred to as 'Arctic' have more restricted distribution in the Arctic than the circumpolar species.
Twelve groups of smut fungi are distributed in Greenland ( Urocystis tothii is not included in this analysis (see the comments to this species). The most numerous distribution groups are the following: • circumpolar-alpine and Arctic-alpine species -14 species; • circumboreal-polar species -10; • circumpolar and Arctic species -6.
With regard to their distribution in Greenland, the established species fall into six groups: • occurring only in North Greenland (2 species A. elynae, A. nardinae, A. rupestris, Microbotryum bistortarum, M. pustulatum, M. silenes-acaulis, M. vinosum, and Urocystis sorosporioides. The most widely distributed smut fungi in Greenland are Anthracoidea bigelowii, A. elynae, Microbotryum bistortarum, and M. vinosum. With regard to the biogeographical zones in the Arctic, the smut fungi established in Greenland occur in the following zones ( The highest number of species are found in the High Arctic. Ten species, Anthracoidea bigelowii, A. capillaris, A. elynae, Microbotryum bistortarum, M. koenigiae, M. pustulatum, M. silenes-acaulis, M. vinosum, Schizonella elynae, and Urocystis sorosporioides, are recorded from all three zones.

Host plants of the smut fungi in Greenland
In the study area, 45 plant species, belonging to 17 genera, were found to be infected by smut fungi (Table 3).
Only plants belonging to six families (Cyperaceae, Poaceae, Juncaceae, Ranunculaceae, Caryophyllaceae, and Polygonaceae), out of a total of 55 in the flora of Greenland, are infected by smut fungi. Cyperaceae is the plant family with the highest number of hosts (23 species) and with the highest percentage of the infected species, compared to the total number of the species in Greenland (39 %) ( Table  4). Carex is the genus with the highest number of host species (22). Both Carex maritima and C. fuliginosa subsp. misandra are infected by three smut fungi, while each of the following five plants, Bistorta vivipara, Carex bigelowii, C. myosuroides, C. nardina, and C. rupestris, is a host of two smut fungi. The total number of the host plants (45 species) is 8.5 % out of a total of 532 vascular plants in the flora of Greenland (Christian Bay, in prep.).

Conclusions
The present work is a first monographic treatment of the smut fungi of Greenland, one of the insufficiently studied areas in the world regarding this taxonomic group of parasitic fungi. The purpose of this investigation was to improve the taxonomic knowledge about the smut fungi of Greenland and the Arctic.