Four decades of new vascular plant records for Greenland.

Abstract Records of new species of vascular plants in Greenland from the last four decades are presented and new phytogeographical data leading to extension of the known distribution limits in Greenland are discussed. Since the publication of the latest edition of the Flora of Greenland in 1978 (Böcher et al. 1978) fieldwork by Greenland Botanical Survey and other expeditions have taken place especially in West and East Greenland and in many remote areas in North and Northeast Greenland. This paper serves as an update of the Flora of Greenland. Twenty species, one subspecies and one new forma have been added to the flora of Greenland: Carex membranacea Hook., Carex miliaris Michx., Carex rhomalea (Fernald) Mack., Equisetum hyemale L., Festuca edlundiae S. Aiken, Consaul and Lefkovich, Festuca groenlandica (Schol.) Frederiksen, Festuca saximontana Rydb., Galium verum L., Geum rossii (R. Br.) Ser., Papaver cornwallisense D. Löve, Papaver dahlianum Nordh., Papaver labradoricum (Fedde) Solstad and Elven, Papaver lapponicum (Tolm.) Nordh., Pedicularis sudetica Willd. ssp. albolabiata Hult., Poa flexuosa Sm., Puccinellia bruggemanni Th. Sør., Ranunculus subrigidus W.B. Drew., Silene vulgaris (Moench) Garcke, Trientalis europaea L. and Veronica officinalis L. in addition to one subspecies Phippsia algida (Sol.) R. Br. ssp. algidiformis (H. Sm.) Löve and Löve. The viviparous form of Poa hartzii f. prolifera has been reported for the first time in Greenland. Presently, the total number of vascular plant species in Greenland is 532. 89 new northern and 28 new southern distribution limits are presented and 26 species are new to the flora province East Greenland, whereas 15 species are new to West Greenland. The numbers of new species to flora provinces North and South Greenland are 14 and one, respectively.


Introduction
Greenland is the largest island in the world, extending from c. 60° to c. 83° northern latitude, and it includes all the Arctic bioclimatic zones (Raynolds et al. 2019) from the subarctic zone in continental areas in southernmost Greenland to the polar desert zone in coastal areas of North Greenland (Bay 1997). Ice-free areas have a varying width of up to 200 km from the outer coast to the Inland Ice. This large variation in climate from coastal to inland areas, in addition to large differences in regional geology and soils, gives rise to a large number of biological niches. Despite this fact only 532 species of vascular plants are known from Greenland, which is a low number considering the size and distribution of the island in all the bioclimatic zones of the Arctic. The immigration of species is restricted because of the remoteness of Greenland to neighboring territories in North America and Eurasia. The species number in the neighboring arctic territories in Canada, Russia, and Norway, which covers larger or smaller areas compared to Greenland, is 375 (Gillespie et al. 2015), 1691 (Sekretareva 2004) and 184 (Alsos et al. 2017), respectively. Generally, the Arctic flora is young with low species diversity, low endemicity, and is little influenced by alien species (Daniëls et al. 2013).
Recently an updated red list of Greenland has been published including all endemic species of vascular plants (Boertmann and Bay 2019).
An updated flora is an important baseline information when assessing the changes in number and species composition in a changing climate in the near future.
The vascular plant flora of Greenland has been studied intensively during the latest decades and three phytogeographical papers have been published based on material in the Copenhagen herbarium (C) and other herbaria. South Greenland was studied by Feilberg (1984), North Greenland by Bay (1992), and West Greenland by Fredskild (1996); in addition the material from East Greenland is under preparation by C. Bay. Taxonomical revisions of species complexes by Solstad and Elven (Papaver complex) and Myhre Pedersen and Elven (Carex saxatilis complex) have added a few species.
The botanical exploration of Greenland started in the easily accessed areas in South and West Greenland, whereas the exploration of the remote areas in North and Northeast Greenland followed decades later. Greenland Botanical Survey at University of Copenhagen carried out floristic and vegetation studies in most parts of Greenland during the period 1962-1998 (Bay et al. 2017).
Since the publication of the Flora of Greenland , one update was made 25 years ago (Bay 1993) that summarized the total number of vascular plant species to 513. During the latest 15 years the total number of vascular plants has been increased by nineteen species giving a total of 532 species. The present paper concerns all the finds of new taxa to Greenland and the new distributional records since the Flora of Greenland was published forty years ago.
An updated flora is an important baseline information when assessing the changes in number and species composition in a changing climate in the near future. An update of the none-native vascular plants in the Arctic has been published recently (Wasowicz et al. 2020).

Methods and materials
Fieldwork in recent years by the Greenland Botanical Survey (GBS) and others (Table  1) have resulted in finds of species new to the flora of Greenland and have extended the knowledge on northern and southern distribution limits for many species. Especially, fieldwork in North and Northeast Greenland in the eighties and nineties, which have been inaccessible for decades because of their remoteness, has added new phytogeographical knowledge. In addition valuable data have been collected from mid-West Greenland when Jon Feilberg and Vilhelm Dalgaard were leaders of the Arctic station on the island Disko.
Several botanist have contributed with important knowledge to the flora of Greenland. B. Fredskild worked in Northeast Greenland ten summers in the period 1982-1996 and more than twenty seasons in West Greenland, while C. Bay worked 29 summers in Greenland, mostly in high arctic areas.
Other important contributors are P. Gelting, G. Seidenfaden, T. Sørensen, F. Rune, G. Halliday, R. Corner, R. and S. David, H. Lang and F. Schwartzenbach, who have contributed with important collections from West, East and North Greenland to the Greenland herbarium of University of Copenhagen. A large number of specimens was collected, identified and stored in C. This information is gathered in the yearly Greenland Botanical Survey reports and is the main basis for this paper together with specimens from other herbaria and recent finds. The nomenclature is according to Böcher et al. 1978.
Of the 532 species in Greenland 89 species (17%) are recorded north of their known northern distribution limit, and 28 species (5%) are recorded south of their known southern limit. Twelve species are new to East Greenland and three are new to West Greenland. The new phytogeographical records are summarized in Table 1 The floristic provinces of Greenland . Equisetum hyemale L.
The boreal species Equisetum hyemale was found in Tasiilaq district, Southeast Greenland (65°53'N) by Daniels and Van Herk (1984). The species is indigenous in Greenland and has probably immigrated to the east coast from Iceland by means of airborn spores.

Festuca edlundiae S. Aiken, Consaul and Lefkovich
Only one specimen of this recently described species is available in C. The collection is from Hold with Hope (73°28'N) in Northeast Greenland. Aiken et al. (2007) indicate that the species is found both in West and East Greenland. These specimens has not been included in the present study.
Festuca groenlandica (Schol.) Frederiksen In Böcher et al. (1978) Festuca groenlandica is included as the var. groenlandica of Festuca brachyphylla. This taxon has been accepted at species level by Frederiksen (1982). Festuca saximontana Rydb. Frederiksen (1982) published the find of this species as a new to Greenland and Fredskild (1996) mapped the distribution in Greenland between 64° and 70°N on the west coast.

Galium verum L.
This boreal species has been found once in Tasiilaq in Southeast Greenland (Gartmann 1990).

Geum rossii R. Br.
This species was found in Lambert Land (79°10'N) during the botanical mapping project in Northeast Greenland (Bay 1992). Only one individual of this Arctic-Alpine species was found in an open fell field vegetation Papaver radicatum complex Hitherto, the Greenlandic material of Papaver has been referred to P. radicatum Rotth. coll. but in the flora ) a few subspecies are mentioned. However, a taxonomical revision by Solstad and Elven concluded that the Papaver radicatum complex consist of four occurring in Greenland: Papaver cornwallisense D. Löve, P. dahlianum Nordh., P. labradoricum (Fedde) Solstad and Elven and P. lapponicum (Tolm.) Nordh. Consequently, P. radicatum Rotth. is excluded from the flora.
All four species occur in East Greenland although P. cornwallisense was only found once in the Scoresbysund area, whereas the other species are widespread (Solstad pers. com.). Pedicularis sudetica Willd. ssp. albolabiata Hult.
The first record of this species new to Greenland was collected in the vicinity of Qaanaaq (77°28'N) in northwest Greenland in 1975, but it was first correctly identified in 1985 as Pedicularia sudetica ssp. albolabiata by Halliday and Lang (1986). The species is only known from five localities in Thule district, Northwest Greenland (Bay 1992).

Poa flexuosa Sm.
This species was recognized and accepted as occurring in Greenland by Gjaerevoll and Ryvarden (1977). Its present distribution in Greenland is from Ingitait Fjord (61°09'N) in Southeast Greenland to Ikorfat (70°45'N) in West Greenland. Nearly all collections in C and AAU are found at an altitude of 450-1400 m a.s.l. (Fredskild 1996).

Puccinellia bruggemanni Th. Sør.
In connection with the phytogeographical study of North Greenland (Bay 1992), the revision of the Puccinellia angustata material revealed 15 collections of a species new to Greenland: Puccinellia bruggemanni Th. Sør. The species was considered as endemic to the Canadian Arctic Archipelago (Aiken et al. 2007), now also including high arctic Greenland (Bay 1992).

R. Elven found this Ranunculus species new to the flora of Greenland among specimens from Northwest and North Greenland during a revision of Ranunculus confervoides Fr. specimens in C. Silene vulgaris (Moench) Garcke
This boreal amphi-atlantic species has been found once in Tasiilaq (66°N) in Southeast Greenland (Gartmann 1990).

Trientalis europaea L.
New to Greenland, found for the first time in 1992 in South Greenland (60°58'N) (Gartmann 1990). This boreal-alpine species is distributed mainly in Europe with its northern outpost in subarctic South Greenland and Iceland.

New subspecies to the flora of Greenland
The subspecies Phippsia algida ssp. algidiformis (H. Sm.) Löve and Löve was found during the phytogeographical work in North Greenland (Bay 1992). It is distributed in high arctic Greenland from Scoresbysund (70°N) in East Greenland through North Greenland to the Thule district in Northwest Greenland (Bay 1992).

New forma to the flora of Greenland
The viviparous form of Poa hartzii Gandoger forma prolifera (Simm.) Boivin has been found three times in Greenland. The localities are close to each other in the easternmost part of North Greenland. Two collections are from Kap København (82°23-24'N) in Peary Land and one from Prinsesse Margrethe Ø southeast of Peary Land. The form is described from material collected at Ellesmere Island and the only other collection outside Greenland is from a small island near Devon Island (Scoggan 1978(Scoggan -1979. The distribution of Poa hartzii s.l. is Amphi-Atlantic high arctic.

Species new to West Greenland
Eriophorum callitrix Cham.
First record is from Qaanaaq (77°28'N) in West Greenland collected by C. Bay in 1988.

Species new to East Greenland
Carex chordorrhiza Ehrh.
Until 1993 the species was only known from a few localities in southernmost Greenland (Feilberg 1984). A. Elvebakk found the species in Jameson Land (71°10'N) on the east coast in 1993 and C. Bay found the species further to the north at Tyroler Fjord (74°28'N) in 2015 -an extension of the distribution area of c. 350 kilometers. Fruits from the species are presumably transported to East Greenland by migrating geese from Iceland.

Carex rostrata Stokes
This species was found at one locality in Skjoldungen district (63°21'N) by C. Bay. It is the first record of Carex rostrata in East Greenland (Fredskild and Bay 1993).
The species was found at two localities in Skjoldungen district by C. Bay. The northernmost at 63°16'N Menyanthes trifoliata L. This species has been found for the first time on the west coast of Jameson Land (71°17'N) during the biological fieldwork prior to an oil exploration (Fredskild, Bay and Holt 1982). Totally, it was found in three lakes.
This species was recorded once in Skjoldungen district (63°21'N) by C. Bay in 1992.

Vaccinium myrtillus L.
This species was found at Kap Niels Juel (63°12'N) by C. Bay and it is only the second record in Greenland. Hitherto it had only been found on the island Alangorssuaq in South Greenland.

Species new to North Greenland
Cardamine pratensis L.
During fieldwork in eastern Peary Land (82°30'N) in 1987 and in Nansen Land (82°58'N) in 1991 collected the first records of the species in North Greenland (Bay 1992).

Carex atrofusca Schkuhr.
Finds by C. Bay in 1985 and in central North Greenland are the first records from North Greenland (Bay 1992). The species has a disjunct distribution in Greenland: In West Greenland it is recorded between Disko (69°16' N and 71°30'N), in Northwest Greenland between Dundas (76°34'N) and Siorapaluk (77°48'N), plus the isolated records from Warming Land and Brainard Sund in North Greenland. In East Greenland it is distributed between Jameson Land (70°38' N) and Lambert Land (79°10' N).
The species was collected at 82°10'N in Wulff Land in 1985 by C. Bay.
Found at Brainard Sund (82°58'N) in Nansen Land which is the first record from North Greenland (Bay 1992). The only other find from North Greenland is from Mylius Erichsen Land (80°20'N) collected by Daniëls in 1995. Dryas octopetala L. ssp. punctata (Juz.) Hult.
This species was collected in Amdrup Land (80°49'N) during the NEWland project in 1993 by C. Bay and B. Fredskild.

Eriophorum callitrix Cham.
C. Bay collected the species in Qaanaaq (77°28'N) in 1988 and in Nansen Land (82°58'N) in central North Greenland in 1991, which are the first records from West Greenland and a new north distribution limit in North Greenland.

Empetrum nigrum L. ssp. hermaphroditum
Empetrum was not known from North Greenland until F. Daniëls visited Mylius Erichsen Land (80°20'N) in 1995 and found a small population at Amdrup Højland. This is the first find in North Greenland, the previous northernmost record was Danmarkshavn (76°46'N) c. 500 km to the south.

Ranunculus nivalis L.
Collected by C. Bay at Kap København in eastern Peary Land (82°30'N), which is the first record from the flora province North Greenland (Bay 1992).

Carex glacialis Mack.
The flora states that it is recorded northward to 73°25'N in West Greenland and has an isolated record at Dundas (76°34'N). It is in addition recorded at six localities in North Greenland, the northern record at 82°10'N in Wulff Land.
During GBS´ work in Northwest Greenland in 1979-1988 the species was found in several localities and the northern distribution limit was extended from 74°22'N to Qaanaaq (77°28'N).

Eriophorum callitrix Cham.
New to West and North Greenland (Bay 1992). It has isolated occurrences in Thule district and Nansen Land collected by C. Bay in 1988 and1991, respectively. Juncus trifidus L.
The species was known from West Greenland between 62°54'N and 72°51'N before it was found at McCormic Ford in Thule district (77°41'N), which extended the northern distribution limit by c. 500 km.
New northern distribution limit at Disko island (70°44'N) in West Greenland.
This species was found at Tugtuligssuaq (75°25'N) in 1979, which is a new north limit for West Greenland (Bay 1992).

North range extensions in East Greenland
Draba fladnizensis Wulf.
In 1990 it was found at Lambert Land extending the northern distribution limit to 79°08'N (Bay 1992).
During the environmental survey prior to an oil exploration in Jameson 1982-1985 the species was found as far south as (70°44'N), which is a new south distribution limit.
R. and S. David collected the species at Tyroler Fjord (74°30'N). This is the northernmost collection in Greenland.
Gymnocarpium dryopteris (L.) Newman Fredskild found Gymnocarpium dryopteris at a hot spring in Liverpool Land (71°08'N) in central East Greenland . This is an extension of the northern distribution limit by more than 200 km.
The collection from 1985 by Fredskild from Liverpool Land (71°08'N) in central east Greenland is a new northern record. Hitherto the species is not found north 69°22 ´N Juncus trifidus L. New north limit in East Greenland at Kuhn Ø (74°44'N) collected by G. Halliday (2019b).
The species was only known from Zackenberg (74°28'N) until the intensive botanical investigations took place in East Greenland in 1989-1990(Fredskild and Bay 1990. The species was found at another ten localities (74°28'-75°55'N) extending the northern distribution limit to Bessel Fj. (75°55'N) (Bay 1992). Corner and Shaw found it further to the north at 76°17'N in 2006.

Mertensia maritima (L.) S. F. Gray
The species is mainly distributed in the Disko-Nugssuaq (68°-72°30'N) in West Greenland and known from Thule district on the west coast. It was found at Zackenberg research station (74°28'N) in East Greenland in 2005 and disappeared few years later. It was presumably brought from West Greenland by a researcher who had worked in central West Greenland before appearing in East Greenland. In East Greenland it is only known from Tasiilaq (66°N) and Skjoldungen (63°N) in addition to Zackenberg.
Found at all localities explored in 1979and 1988in Northwest Greenland (Fredskild and Bay 1990) and East Greenland in 1989-1990(Fredskild and Bay 1991, Bay 1992. The known distribution limit is now at 77°48'N in Northwest Greenland and 79°08'N in Northeast Greenland (Bay 1992).
New northern distribution limit at Milne Land (70°04'N) by C. Bay in 2014.
Until 1989, when it was found at Droning Louise Land (76°52'N) during the biological mapping of East Greenland, the species was recorded northwards in East Greenland to Clavering Ø (74°20'N).

Arnica angustifolia M. Vahl
This species has been found four times in central north Greenland; northernmost find at 83°04'N collected by C. Bay in 1985(Bay 1992.
The species was collected at 82°10'N in Wulff Land in 1985 by C. Bay.

Epilobium arcticum Sam.
F. Schwartzenbach collected the species at Frigg Fj. (83°15'N), this is only the third find in the flora province North Greenland. Previously, it has been collected at Centrum Sø (80°10'N).
New north limit at Brainard Sund, Nansen Land (82°58'N), which is only the sixth record from North Greenland (Bay 1992).
New to western North Greenland. Hitherto only known from four localities in North Greenland (Bay 1992). It was collected at two localities in Warming Land in central North Greenland in 1985 (Aastrup et al. 1986).

Antennaria angustata Greene
The species was found at Isua (65°12'N) in West Greenland by Bay and Simonsen (2013).
The species was found on the east coast of Disko Island 69°54'N (Fredskild 1996).
Found by C. Bay during fieldwork in 2009 and 2013 south of the southern distribution limit. The southernmost find is at 65°32'N.
The new south record at Isua in West Greenland (65°12'N) was recorded in 2012 (Bay and Simonsen 2013).

Carex rupestris All.
This northern species has extended the southern distribution limit to 63°59'N in West Greenland.

Draba cana Rydberg
Found at Narsaq (61°N) by Simonsen in 2014. This is an extension of the south distribution limit by 400 kilometers.

X Ledodendron vanhoeffeni (Abromeit) Dalgaard and Fredskild.
The species was only known from one locality in central West Greenland (Böcher et al. 1978), but the knowledge of the distribution has been extended by eight finds in central West Greenland southward to 66°30'N (Dalgaard and Fredskild 1993).

Luzula arctica Blytt
This northern distributed species was found at a new southern distribution limit in West Greenland during fieldwork in the mining area Isua in West Greenland (Bay and Simonsen 2013).

South range extensions in East Greenland
Calamagrostis purpurascens R. Br.
The species was found at six localities during a Greenland Botanical Surveys expedition to Skjoldungen district in 1992. The southernmost record was at 63°21'N and it is an extension of the distribution area of c. 700 km to the south.

Draba fladnizensis Wulf.
The find of Draba fladnizensis in Skjoldungen district (63°28'N) was an extension of the species east Greenland distribution to the south; hitherto known from East Greenland between Jameson Land (70°N) and Lambert Land (79°10'N).
Corrections to the Flora of Greenland  During the study of the vascular plant flora of East Greenland a few corrections to the flora of Greenland  showed up.

Callitriche anceps Fern
No collections from Skjoldungen district have been found in herb. C, BM, LANC or O as stated in the flora of Greenland. Consequently, the species is strictly distributed at the west coast of Greenland.

Callitriche palustris L.
Northernmost record is from 71°17'N in East Greenland and not as stated in the Flora of Greenland at 72°40'N.

Hippuris vulgaris L.
Recent studies show that Hippuris lanceolata Retz. is the most common species in the Western Arctic (Elven et al. 2012). It is the only species documented from Greenland and the Canadian Arctic Archipelago; its two relatives (Hippuris tetraphylla L. f. and H. vulgaris L.) occur together with H. lanceolata on the American mainland, but not in Greenland.
The northernmost locality is Siorapaluk (77°48'N) in West Greenland (Fredskild and Bay 1988) and Mørkefjord (77°55'N) in East Greenland. No specimens of Honckenya peploides has been found in Inglefield Land, which is the northern limit according to Böcher et al. (1978).

Subularia aquatica L.
No evidence has been found of Subularia aquatica L. occurring at 69°43'N in East Greenland. Consequently, the northernmost find in East Greenland is at 65°39'N Woodsia ilvensis (L.) R. Br. Böcher et al. (1978) states that the species is not recorded north of 71°N in East Greenland. However, a specimen from Hold with Hope (73°33'N) by Hartz from 1891 is the northernmost collection from East Greenland.

Conclusions
The number of vascular plant taxa in the flora of Greenland The latest update of the number of vascular species of the flora of Greenland, which is 25 years old (Bay 1993) summarized the total number to 513. During the latest 25 years the total number of vascular plants has been increased by twenty species giving a total of 532 species. Holt et al. (2019) recently presented a photo flora on the internet totaling 625 species of vascular plants including introduced species and planted tree species.