Inuit Nunangat, the Inuit homeland, stretches across Canadian Arctic lands and waters and spans the four Inuit regions: the Inuvialuit Settlement Region, Nunavut, Nunavik and Nunatsiavut. Inuit Nunangat is a distinct geographic, cultural and political region within Canada (Government of Canada 2022). Formerly part of the Northwest Territories, Nunavut became a Canadian territory on 1 April 1999. It comprises more than one-fifth of Canada and includes more than two-thirds of the country’s shoreline. Nunavut is divided into three regions: Kitikmeot, Kivalliq and Qikiqtaaluk. Of these, the Qikiqtaaluk Region is the easternmost, largest and most populated. Baffin Island is part of the Qikiqtaaluk Region. The Inuktitut word qikiqtaaluk means “very big island.” Hudson Strait separates Baffin Island from the Canadian mainland and Baffin Bay and Davis Strait separate it from Greenland. Southern Baffin Island includes Meta Incognita Peninsula, a highland area reaching an elevation of ca. 914 m (Fig. 1B). Hudson Strait bounds Meta Incognita Peninsula to the south, Frobisher Bay bounds it to the north and the peninsula extends inland to Amadjuak Lake, Baffin Island’s second-largest lake.

The Soper River on Meta Incognita Peninsula (Fig. 1C, D) is southern Baffin Island’s largest river. Its source is a lake at ca. 63°30'39"N, 69°37'28"W, from which the river flows 108 km into Hudson Strait. Numerous small streams, basins and rivers feed the Soper River, draining some 2,500 km². Its major tributaries are the Joy, Willow, Livingstone and Cascade rivers. The Soper River valley ranges from ca. 0.5 km to 1.2 km wide (Soper 1936). In Inuktitut, the Soper River is called Kuujuaq, which means “big river” (Laird and Associates 2004). The river is navigable for ca. 50 km (Laird and Associates 2004). Naturalist Joseph Dewey Soper explored and mapped the river in June and July 1931; he called it the Koukdjuak River. The Geographic Board of Canada named the river and the lake into which it runs after J.D. Soper in 1946 to avoid confusion with Baffin Island’s Koukdjuak River that flows out of Nettilling Lake. The Canadian Heritage Rivers System declared the Soper River a Canadian Heritage River in 1992. The Soper River’s roles within the Canadian Heritage Rivers System include “to highlight an outstanding river environment which exemplifies the natural ecosystem and geological history of the southern Baffin region” and “to encourage protection, future scientific research and public understanding of the full range of natural and cultural heritage values of this northern region with a focus on the Soper River” (Laird and Associates 2004: 9).

The Soper River is a central feature of Katannilik Territorial Park (1,262 km²; Fig. 1C, D), established in 1993. At that time, the park fell within the Northwest Territories. Now it is part of Nunavut, administered by the Nunavut Department of Environment’s Parks and Special Places division. Nunavut’s territorial parks aim to protect cultural and natural landscapes, enhance community and visitor experience and engage the community in heritage appreciation and conservation (Government of Nunavut 2022). The Inuktitut word katannilik means “where there are waterfalls,” referring to the many falls and rapids that occur along or feed the Soper River. The park offers numerous recreation activities, including canoeing, kayaking, rafting, hiking and camping. The 120 km Itijjagiaq Trail, a traditional travel route between the communities of Iqaluit and Kimmirut, runs through the park (Laird and Associates 2004). The trail traverses the park from Bay of Two Rivers (Nunngarut Bay) on Frobisher Bay to Kimmirut, south of the park. Itijjagiaq Trail is part of the Trans Canada Trail, the world’s longest trail network (Trans Canada Trail 2021). Amenities along the trail within the Soper River valley include eight emergency shelters, a large group cabin near Mount Moore and a campground near Soper Falls (Laird and Associates 2004).

The Soper River enters Katannilik Territorial Park ca. 13 km north-northwest of Mount Joy (elevation 562 m). Mount Joy, just north of the Joy and Soper rivers’ confluence, is one of the park’s prominent geographic features. It portrays a human face on its southern slope; Soper (1933) illustrated this. The Soper Heritage River Guide Map refers to several geographic features near Mount Joy by unofficial names (Anonymous no date). “Paradise Flats,” a large terrace immediately east of Mount Joy, includes a gravel landing strip where small aircraft drop paddlers embarking on a river trip. “Panorama Flats” and “Panorama Creek” are northeast of “Paradise Flats”. “Veil Creek” feeds the Soper River southeast of “Paradise Flats”. “Cascade Rapids” occur along the river, ca. 10 km south of Mount Joy. Approximately 0.5 km further south, the Soper and Cascade rivers meet on the Soper River’s east side. Soper (1936:434) described the Cascade River as “wild and tumultuous”. Two falls (“Cascade Falls”) occur along the Cascade River: a smaller one ca. 1 km upriver that drops ca. 4.5 m and a larger one another 3 km upriver that drops ca. 29 m (Soper 1936). Some 14.5 km south of Mount Joy, the Willow River meets the Soper River on its west side. Some 3.5 km further south, the Livingstone and Soper rivers meet on the Soper River’s west side. Along the Livingstone River just above the confluence are “Livingstone Falls,” which drop 3 m over a 30 m ledge. About 50 km south of Mount Joy, the Soper River falls ca. 6 m along a 0.5 km series of rapids, Soper Falls. Below Soper Falls is Tasiujarjuaq (formerly Soper Lake), a lake fed by freshwater and saltwater. The Inuktitut word tasiujarjuaq means “big lake-like lake”. At high tide, saltwater flows into Tasiujarjuaq from Pleasant Inlet, which is immediately south of the lake and extends ca. 10 km from north-western North Bay. North Bay is a large bay on Hudson Strait’s north side that extends from Imiligaarjuit (formerly Cape Tanfield), ca. 26 km southeast of Kimmirut, to ca. 26 km west-northwest. At low tide, freshwater flows from Tasiujarjuaq into Pleasant Inlet. Just east of Pleasant Inlet is Glasgow (Westbourne) Bay, a large inlet that extends northwest ca. 18 km from North Bay.

Humans have occupied the North Bay area for thousands of years, dating to the pre-Dorset period (4500–2700 B.P.) (Maxwell 1973; Milne and Park 2016). Today, the Hamlet of Kimmirut is at the head of Glasgow Bay. The Inuktitut word kimmirut means "heel", referring to a marble outcrop near the community resembling the heel of a foot. Until 1 January 1996, Kimmirut was named Lake Harbour. An Anglican Church was erected in the community in 1909 and the Hudson’s Bay Company set up a trading post there in 1911. Qikiqtani Inuit Association (2013) recorded the history of the Kimmirummiut, the area’s people. Kimmirut’s area is 2.27 km² and its elevation is 53 m. Its population in 2016 was 398 (Statistics Canada 2017). Kinngait (formerly Cape Dorset) is the only other settlement on Baffin Island’s south coast, 364 km northwest.

The Soper River valley’s substrate is mainly till, outwash, deltaic gravel and sandy alluvium. Calcareous outcrops, including marble and crystalline limestone, occur just north of the Soper and Livingstone rivers’ confluence (Soper 1936; St-Onge et al. 1996). Much of the plateau above the Soper River valley comprises granitic layered tonalites and gneiss (Soper 1936; St-Onge et al. 1996). An enclave of Inuit Owned Land surrounded by the park contains surface deposits of lapis lazuli, mica and garnet (Hogarth 1971; Grice and Gault 1983). The park’s bedrock mostly comprises Cumberland batholith monzogranite, with small areas of Lake Harbour Group metasedimentary rocks (marble and monzogranite) and Ramsay River orthogneiss (Hodgson 2005).

Soper (1933, 1936) briefly described the area’s vegetation, which becomes more luxuriant as the Soper River valley ascends. Near the coast, willows range from prostrate to 30–60 cm tall, while further up the valley, they reach more than 3.5 m tall. Soper (1933:133) published a photograph of these tall willows. Nicholas Polunin (1948) described Lake Harbour’s vegetation. He included species lists of vascular plants, bryophytes and lichens typical of common habitats. He focused on hill summits and slopes, lowlands, marshes, snow patch habitats, “flower slopes” (lushly vegetated south-facing slopes), freshwater habitats and seashore habitats. Figs 2–5 show the study area’s habitat diversity.

Figure 2. 

Images from Joseph Dewey Soper’s 1931 explorations along the Koukdjuak [Soper] River A J.D. Soper and one of his Inuit companions, Matuse or Matoosa, with willows 12'6" [3.8 m] high that grew at the mouth of the Willow River, a tributary to the Koukdjuak [Soper] River, 1 July 1931 [Library and Archives Canada MIKAN No. 5277159] B Matuse or Matoosa standing amongst willows 4'–5' [1.2–1.5 m] high along a tributary brook of the Koukdjuak [Soper] River, 1 July 1931 [Library and Archives Canada MIKAN No. 5277158] C looking down on the valley of the Koukdjuak [Soper] River (eastwardly) from a height of 1200' [366 m], (9:30 in the evening), 1 July 1931 [Library and Archives Canada MIKAN No. 5277160] D a view across the valley of the Koukdjuak [Soper] River to the northeast, 2 July 1931 [Library and Archives Canada MIKAN No. 5277161] E noon halt at rapids on the Koukdjuak [Soper] River, 30 June 1931 [Library and Archives Canada MIKAN No. 5277156] F patching canoe after a fight in the rapids of the Koukdjuak [Soper] River, 30 June 1931 [Library and Archives Canada MIKAN No. 5277157]. Credit: Joseph Dewey Soper/Department of Indian Affairs and Northern Development fonds/Library and Archives Canada/Public domain.

Figure 3. 

Habitat diversity within Katannilik Territorial Park A “Panorama Flats” and “Panorama Creek” (left) and the Soper River running past Mount Joy (right), 2 July 2012 B tundra depressions dominated by Betula glandulosa on “Panorama Flats”, 5 July 2012 C Betula glandulosa–Rhododendron tomentosum subsp. decumbens-dominated dry tundra on “Panorama Flats”, 30 June 2012 D moist tundra along the edge of Soper River, with Corallorhiza trifida, 1 July 2012. E “Panorama Falls”, 2 July 2012 F mesic tundra along Soper River, south of Mount Joy, 5 July 2012 G group/warden cabin # 7 beside Soper River, 6 July 2012 H dry, gravelly hills with Salix uva-ursi, 6 July 2012. Photos A, E, G by L.J. Gillespie, B, C, F by J.M. Saarela and D, H by R.D. Bull.

Figure 4. 

Habitat diversity within Katannilik Territorial Park. A wet sedge meadow near Cascade River, 6 July 2012 B dry tundra with Betula glandulosa die-off near Willow River, 8 July 2012 C dry flats at the confluence of the Soper and Livingstone rivers, 12 July 2012 D crystalline limestone outcrops over gravelly hills at the confluence of Soper and Livingstone rivers, 12 July 2012 E R.D. Bull near a lake atop the plateau west of the confluence of Soper and Livingstone rivers, 11 July 2012 F sandy depressions on flats at the confluence of Soper and Livingstone rivers, dominated by Chamaenerion latifolium, Saxifraga cernua and Artemisia borealis, 11 July 2012 G wet pond margin near the confluence of Soper and Livingstone rivers, with a large population of Carex microglochin, 12 July 2012 H shallow tundra ponds along Soper River near Salix planifolia stand, 13 July 2012. Photos A–C, E, F by L.J. Gillespie, D, G by J.M. Saarela and H by R.D. Bull.

Figure 5. 

Habitat diversity within the study area A lapis lazuli deposit on the west bank of the Soper River, 16 July 2012 B hummocky sedge meadow on the east bank of Soper River, near Soper Falls, 17 July 2012 C wet, sandy flats near the campground at Soper Falls, with Eleocharis acicularis, 17 July 2012 D dry, sandy flats south of Soper Falls, with Salix arctica, Agrostis mertensii and Cerastium, 18 July 2012 E Kimmirut, 20 July 2012 F Fundo Lake, Kimmirut, 22 July 2012 G enriched vegetation near Kimmirut dump and sewage outlet, 22 July 2012 H coastal shoreline and dry ridges near Pleasant Inlet, 21 July 2012. Photos A by P.C. Sokoloff and B–H by J.M. Saarela.

The Arctic bioclimate zone has an Arctic climate, Arctic flora and tundra vegetation. The Circumpolar Arctic Vegetation Map divided this circumpolar zone into five bioclimate subzones named A to E, defined by summer temperature and vegetation characteristics (Elvebakk 1999; CAVM Team 2003; Walker et al. 2005). Subzone A is restricted in Canada to the north-western Queen Elizabeth Islands. It is the coldest and harshest subzone, characterized by a 0–3 °C mean July temperature, < 5% vascular plant cover, vascular plant growth low to the ground (barely exceeding the height of mosses, woody plants absent) and local vascular floras with fewer than 50 species. Subzone E is restricted in Canada to the mainland. It is the warmest subzone, characterized by a 9–12 °C mean July temperature, 80–100% vascular plant cover, a 20–50(–80 cm) tall herbaceous/dwarf-shrub layer and local vascular floras with 200 to 500 species.

Southern Baffin Island spans two bioclimate subzones. The ca. western third of Foxe Peninsula and adjacent islands fall within Subzone C. This subzone has a 5–7 °C mean July temperature, 5–50% vascular plant cover, a moss layer 3–5 cm thick, a herbaceous layer 5–10 cm tall, dwarf shrubs less than 15 cm tall and local vascular floras with 75 to 150 species. The rest of southern Baffin Island, including the study area, falls within Subzone D, which extends north to ca. 67°47'N. This subzone has a 7–9 °C mean July temperature, 50–80% vascular plant cover, a moss layer 5–10 cm thick, herbaceous and dwarf shrub layers 10–40 cm tall and local vascular floras with 125 to 250 species. Elsewhere in Canada, Subzone D includes southern Banks, Southampton and Victoria islands and much of the mainland Arctic. Following earlier North American Arctic vegetation classifications, the study area's vegetation is Low Arctic (Polunin 1951; Bliss 1997), low erect shrub tundra (Edlund and Alt 1989; Edlund 1990), southern Arctic dwarf shrub tundra (Daniëls et al. 2000) or erect dwarf shrub tundra (Walker et al. 2002). The Soper River valley’s dominant circumpolar vegetation is erect dwarf shrub tundra, i.e., shrubs mostly less than 40 cm tall (CAVM Team 2003). Elsewhere on Baffin Island, this vegetation occurs in three areas of Meta Incognita Peninsula (two east of the Soper River and one along Frobisher Bay), near the tip of Hall Peninsula and near Pangnirtung (CAVM Team 2003).

Researchers divide the circumpolar Arctic into 21 floristic provinces, delimited primarily based on vascular plant species distributions (Elven et al. 2011). The study area falls within the Hudson Bay–Labrador Region comprising Hudson Bay’s shores and islands (including Southampton Island and its small surrounding islands), Ungava Peninsula, northernmost Labrador Peninsula and southern Baffin Island, north to Cumberland Sound. The region’s flora has a boreal American influence.

The study area’s climate is Tundra (class ET) according to the Köppen-Geiger climate classification, characterized by an average temperature of the warmest month between 0 °C and 10 °C (Beck et al. 2018). Models predict that, by 2071–2100, the study area’s climate will be Subarctic (class Dfc), characterized, in part, by one to three months averaging above 10 °C (Beck et al. 2018). Meteorological station Kimmirut A records weather data for Kimmirut, but long-term data for the 1981–2010 climate normals period (i.e., three-decade averages of climate variables) are lacking. The nearest stations on Baffin Island with data for the 1981–2010 climate normals period are Cape Dorset A (Environment Canada 2021a) to the northwest and Iqaluit A (Environment Canada 2021b) to the north-northeast. During the 30-year period, Kinngait (formerly Cape Dorset) had a -8.9 °C ± 4.3 mean annual air temperature, a 7.8 °C ± 1.2 mean July temperature and a -25.4 °C ± 2.8 mean February temperature. Iqaluit had a -9.3 °C ± 3.7 mean annual air temperature, an 8.2 °C ± 1.0 mean July temperature and a -27.5 °C ± 4.4 mean February temperature. Kinngait’s annual precipitation was 418.5 mm; ca. 38% fell as rain and the rest as snow. Iqaluit’s was 403.7 mm; ca. 49% fell as rain. According to Nunavut Parks & Special Places (2008), the sheltered Soper River valley is four to five degrees Celsius warmer than the surrounding areas, including Kimmirut. We are unaware of long-term climate data for the valley.

Collectors have gathered botanical specimens in the study area throughout the last century, beginning in the late 1920s. Botanist Malte Oscar Malte, then head of the National Herbarium of Canada, National Museum of Canada (now the Canadian Museum of Nature), travelled to Lake Harbour four times aboard Hudson’s Bay Company’s RMS Nascopie as part of the 1927, 1928 and 1933 Eastern Arctic Patrols. He collected at Lake Harbour on 1–2 and 25–26 August 1927, 29–30 August 1928 and 22 July 1933 (Malte 1934; Polunin 1940). Malte died soon after his last visit to Lake Harbour, having become ill on Charlton Island in James Bay during the 1933 patrol (Smith and Lackenbauer 2014). Danish biologist Frits Johansen collected 33 vascular plant species near Lake Harbour on 23 August 1927, during the Canadian Hudson Strait Expedition, “… in the outer part of the sailing into the post, … between a larger island … and the ‘Meta incognita’ part of Baffin Island…” (Johansen 1934). Joseph Dewey Soper collected plants while living in Lake Harbour in the early 1930s (Dalton 2010). In 1931, he collected at Lake Harbour on 21 June, 26 June, 5 July and 7 July and near the rapids [Soper Falls] of the Koukdjuak [Soper] River on 25 June. On 1 July 1931, he canoed up the Koukdjuak [Soper] River with two Inuit companions, Moosa and Mutuse, and collected inland (Fig. 2). Botanist Nicholas Polunin was part of the 1934 Eastern Arctic Patrol and collected in Lake Harbour from 30–31 August (Polunin 1940). Polunin returned to Lake Harbour two years later with the 1936 Eastern Arctic Patrol and again collected there from 26–28 July (Cockburn 1983). Alice M. Tallman, recorded on her labels as Mrs. George K. Tallman, also traveled with the 1936 Eastern Arctic Patrol. She collected a few specimens at Lake Harbour on 27 July (MIN) (Hudson’s Bay Company Archives, Gertrude Perrin fonds, HB2008/004) (Cockburn 1983). Père Arthème Dutilly joined the 1936 Eastern Arctic Patrol in Churchill and collected in Lake Harbour from 26–28 August (Smith and Lackenbauer 2014). Dutilly collected again in Lake Harbour on 28 August 1941. Norman Bethune Sanson, Banff Park Museum curator from 1896 to 1931 (Bird 1976), collected at least two specimens in Kimmirut on 17 August 1938. Though we are unaware of published accounts of Sanson’s Arctic fieldwork, label data from HUH, NYBG and TRT and specimen citations in Ball (1950) indicate he also collected that year at Fort Ross (Somerset Island), Pond Inlet and Clyde River (Baffin Island), Chesterfield Inlet, and Port Burwell (Killiniq Island). Margaret Oldenburg (Grand Marais, Minnesota), a former librarian who undertook numerous expeditions to the Canadian Arctic to collect plants from the late 1930s to the mid-1950s, visited Kimmirut with the 1939 Eastern Arctic Patrol and collected there on 22–23 July (University of Minnesota Archives, Margaret Oldenburg fonds). Given they were only in the area for one to two days during brief stops, we assume Malte, Polunin, Dutilly and Oldenburg collected in the immediate Lake Harbour settlement area. Canadian Arctic floristic treatments have considered most of the 1920s and 1930s collections from the study area (Polunin 1940; Porsild 1957, 1964; Porsild and Cody 1980; Aiken et al. 2007).

We know of few collections gathered in the study area between 1940 and the early 2000s. Weston Blake Jr. collected one specimen at a site just east of Kimmirut on 27 June 1965, while conducting geologic research on southern Baffin Island as part of “Operation Amadjuak” (Blake 1966). Peggy Fleming, US National Parks Service (Fleming and Raclare 1995), collected two specimens near the Livingstone and Soper rivers’ confluence on 26 July 1992, while on vacation canoeing the Soper River (P. Fleming, personal communication).

Botanists again visited the study area in the first decade of the 21^st century. Susan Aiken (Canadian Museum of Nature) and her associate Rosalind Iles collected in the Soper River valley in 2002. Many of their collections are vouchers for photographs published in the Flora of the Canadian Arctic Archipelago (Aiken et al. 2007). Annie Archambault collected in Kimmirut from 4–5 August 2005, while conducting fieldwork for her Ph.D. research on Oxytropis DC. (Fabaceae) (Archambault 2013). We collected in the area in 2012.

We studied the flora of Katannilik Territorial Park and vicinity from 30 June to 23 July 2012. We conducted research under a Nunavut Territorial Parks Use Permit, Nunavut Wildlife Research Permit WL 2012-034, Nunavut Water Board Permit 3 BC-FAA1212, Qikiqtani Inuit Association Certificate of Exemption (Access to Inuit Owned Land) Q12X016 and Polar Continental Shelf Program Project Number 515-12. We explored botanical diversity along the Soper River while travelling by inflatable canoe from Mount Joy to Soper Falls. We spent 20 days within the park and four days outside the park, in Kimmirut and vicinity.

We flew from Iqaluit to “Paradise Flats” near Mount Joy, our starting point, by Twin Otter plane, which landed on the airstrip there. We established six field camps along the Soper River: at the airstrip (30 June to 5 July; 63°14'52"N, 69°36'28"W), at group/warden cabin #7 (6–9 July; 63°09'44"N, 69°39'28"W), at the Livingstone River and Soper River confluence (10–12 July; 63°06'33"N, 69°43'46"W), on the east riverbank south of emergency shelter #8 (13–15 July; 62°59'02"N, 69°43'01"W) and at the Soper Falls campground (17–19 July; 62°54'33"N, 69°50'12"W). We established a final camp at Taqaiqsirvik Territorial Park (campground) in Kimmirut (20–23 July; 62°50'56"N, 69°53'18"W). We explored each camp area on foot, seeking out as many habitats as possible and aiming to record all vascular plant species present in each area with at least one collection. While travelling between camps, we stopped to collect at two willow thickets along the river (13 July) and the lapis lazuli occurrence (16 July). Labels on our specimens from the lapis lazuli site (Saarela et al. 2496–2506) mistakenly indicate it is within Katannilik Territorial Park; it is not. On 17–18 July, we collected near Soper Falls. On 19 July, we collected on a small unnamed island within Tasiujarjuaq and outside the park, around the Kimmirut boat landing and Reversing Falls. On 20, 22 and 24 July, we collected in Kimmirut and vicinity. On 21 July, we collected along Pleasant Inlet, west of Kimmirut, travelling via a boat charter from the hamlet. Fig. 6 shows the locations of our collecting sites and Table 1 describes them. We assigned a code to each site with unique geographical coordinates and grouped them, based on the general collection area, which usually corresponds to our camp locations. We reference these codes in the annotated checklist.

Figure 6. 

Vascular plant collection sites along the lower Soper River A sites where collections were made before 2012 B sites where we collected plants in 2012.

We dried specimens in a standard plant press in the field. During processing, we subsampled specimens for a small amount of leaf tissue preserved in silica gel desiccant; we tagged the plant subsampled when possible. We have deposited all tissue samples in the Canadian Museum of Nature’s National Biodiversity Cryobank of Canada. J.M. Saarela, P.C. Sokoloff and L.J. Gillespie identified specimens. We have deposited a complete set of specimens in the National Herbarium of Canada (CAN) at the Canadian Museum of Nature and have distributed duplicates to the following herbaria, as indicated in the specimen citations: University of Alaska Museum of the North (ALA); University of Alberta Vascular Plant Herbarium (ALTA); Arizona State University (ASU); Gray Herbarium, Harvard University (GH); University of Michigan (MICH); Bell Museum, University of Minnesota (MIN); Missouri Botanical Garden (MO); Marie-Victorin Herbarium, University of Montreal (MT); The Rooms Provincial Museum, Newfoundland and Labrador (NFM); William and Lynda Steere Herbarium, New York Botanical Garden (NY); Botanical Museum, Oslo (O); Herbier Louis-Marie, Université Laval (QFA); Norwegian University of Science and Technology (TRH); Beaty Biodiversity Museum, University of British Columbia (UBC); United States National Herbarium, National Museum of Natural History, Smithsonian Institution (US); Intermountain Herbarium, Utah State University (UTC); University of Victoria (UVIC); University of Manitoba Herbarium (WIN); Wilfred Laurier University (WLU); University of Washington (WTU).

To generate a comprehensive checklist of the study area’s vascular flora, we attempted to account for all plant collections gathered therein. We searched the literature, herbaria and online collection databases to locate vascular plant specimens collected in the study area. We manually searched the collections at CAN, DAO, MIN, QFA and H (where we only searched through the monocots). Through direct enquiries to collection managers and searches on the Global Biodiversity Information Facility (GBIF) platform, we examined and confirmed specimen images from the E.C. Smith Herbarium at Acadia University (ACAD), ALTA, the general herbarium of vascular plants at the University of Copenhagen (C), the herbarium at the Field Museum of Natural History (F), GH, the herbarium at the Royal Botanic Gardens, Kew (K), the R.L. McGregor Herbarium at the University of Kansas (KANU), the herbarium at the Botanical Museum, Lund University (LD), MICH, MIN, MO, MT, the herbarium at McGill University, Macdonald Campus (MTMG), NY, O, the herbarium at the Swedish Museum of Natural History (S), the Green Plant Herbarium, Royal Ontario Museum (TRT), US, UTC and the herbarium at the Royal British Columbia Museum (V).

Malte’s specimen labels do not include collection numbers, but they bear unique six-digit numbers from an older National Herbarium of Canada number series. We used these numbers to identify duplicate specimens amongst herbaria and we cite this number in square brackets for each of Malte’s collections in the checklist to unambiguously refer to them. In addition to the specimen label from the National Herbarium of Canada, a subset of Malte’s collections housed at GH include handwritten collection numbers on separate pieces of paper, which we assume are fragments of the paper in which he pressed his specimens. To match numbered collections at GH with duplicates at CAN and elsewhere that exclude these numbers, we relied on the six-digit number on the label. We cite these in the checklist as s.n./[collection number] followed by the six-digit number in square brackets.

Soper’s specimen labels indicate that on 1 July 1931, the day he canoed upriver, he collected at 63°10'N, 69°55'W. These coordinates, however, point to a location 11.5 km northwest of the Soper and Livingstone rivers’ confluence on the plateau west of the Soper River. Dalton (2010) stated that, during this trip, the team stopped to collect at 63°50'N, but this is also an error because this latitude is north of Iqaluit. Soper (1936) described willows up to 12 ft [3.7 m] high at this location. He indicated that the group lined their canoe from this collecting locality ca. 3 mi [4.8 km] upriver while passing “rapids, cascades, and falls” and that two-thirds of the way up the river, the group reached a large waterfall, which he named “Cascade Falls.” The Soper and Willow rivers’ confluence is ca. three miles south of Cascade River, so we infer that on 1 July 1931, Soper collected around the large willow patch (Salix planifolia Pursh) at the mouth of the Willow River, an area now part of Katannilik Territorial Park.

We combined all data obtained from physical and online herbarium searches into a spreadsheet (Suppl. material 1). We manually cleaned the dataset to standardize collector names, date format and locality descriptions amongst specimens gathered by the same collector at the same site. We combined records of duplicate specimens housed in different herbaria into single records, maintaining information on their disposition(s). Most of the earlier collections either lacked geographical coordinates or had imprecise ones. We georeferenced these sites following standard point-radius protocols, including estimates of coordinate uncertainty in metres. Fig. 6 shows the general locations of previous collectors’ collecting sites. We made maps with ArcMap 10.5.1 (Esri, Redlands, California 2016).

We summarize the study area’s vascular flora in an annotated checklist. Lycophyte and monilophyte classifications follow Pteridophyte Phylogeny Group (2016). Angiosperm classification follows Angiosperm Phylogeny Group IV (2016). Within families, genera and species are listed alphabetically. We base taxonomy at genus, species and infraspecific levels on consideration of relevant global literature, including Elven et al. (2011), Flora of North America treatments (Flora of North America Editorial Committee 1993+) and recent revisions and nomenclatural updates, including Wiegleb et al. (2017), Barberá et al. (2019) and Morin (2020). For each species, we list selected synonyms, focussing on names used in critical Canadian (Polunin 1940; Porsild and Cody 1980; Aiken et al. 2007; Payette 2013, 2015, 2018) and international (Elven et al. 2011) Arctic taxonomic treatments, recent national or continental treatments, particularly Flora of North America, and other relevant taxonomic works. English common names follow Brouillet et al. (2010+). Global distribution summaries follow Elven et al. (2011). For all of our 2012 collections, the list of collectors is J.M. Saarela, L.J. Gillespie, P.C. Sokoloff and R.D. Bull; we abbreviate this in the checklist as Saarela et al.

In the annotated checklist, we indicate whether each taxon has been previously recorded in Kimmirut or Katannilik Territorial Park (i.e., from within the area currently the park). Previously recorded means the taxon was mentioned or mapped in the study area in one or more publications (Polunin 1940; Porsild 1957, 1964; Porsild and Cody 1980; Aiken et al. 2007). Usually, one or all vouchers we cite are the ones previous authors cited or mapped. Polunin (1940) cited voucher material from the study area, except for some common taxa he recorded as “everywhere-numerous records from almost all localities” (e.g., Carex membranacea). Later authors, however, did not cite the specimens they mapped (Porsild 1957, 1964; Porsild and Cody 1980; Aiken et al. 2007). We also indicate taxa newly recorded for Kimmirut, the park, Pleasant Inlet and the study area. New records include collections we made in 2012, older collections overlooked in earlier publications and collections known to previous authors that were misidentified or for which a taxonomic concept has been revised. For all taxa recorded in the study area, we cite one or more specimens.

We also summarize the known distribution on Baffin Island for each taxon recorded in the study area. These summaries include site-level descriptions of collection localities on the Meta Incognita Peninsula, Foxe Peninsula and Hall Peninsula, as well as on islands immediately adjacent to Baffin Island, such as Dorset, Mallik and Resolution islands. We refer to these regions as southern Baffin Island. Sometimes, we summarize all known occurrences of a taxon on Baffin Island (for example, for taxa known from few collections across the island). We based these summaries on published literature, primarily Aiken et al. (2007) and Global Biodiversity Information Facility (GBIF)-mediated collection data that have not been published or included in maps. We accepted records discovered on GBIF for which we could confirm a specimen determination, based on an image. For all sites on Baffin Island for which records have not been published, we cite the collector, collector number, herbarium and accession or barcode number. Furthermore, through careful cross-checking of vouchered occurrence data on GBIF with distribution maps from Aiken et al. (2007), based primarily on material housed at CAN, we revealed some mapping errors; we describe these errors in the text.

We previously published a subset of our 2012 collections that are new records for one or more of Baffin Island (or, in one case, where known from one previous record), the eastern Canadian Arctic Archipelago, the Canadian Arctic Archipelago or Nunavut (Gillespie et al. 2015). These taxa are Cryptogramma stelleri (S.G.Gmel.) Prantl (Pteridaceae), Carex brunnescens (Pers.) Poir. subsp. brunnescens (Cyperaceae), Calamagrostis neglecta subsp. groenlandica (Schrank) Matuszk. (as C. stricta subsp. groenlandica (Schrank) Á.Löve), Hordeum jubatum L. subsp. jubatum, Leymus mollis (Trin.) Pilg. subsp. mollis (Poaceae), Triglochin palustris L. (Juncaginaceae), Corallorhiza trifida Châtel., Platanthera obtusata (Banks ex Pursh) Lindl. subsp. obtusata (Orchidaceae), Arenaria longipedunculata Hultén (Caryophyllaceae), Orthilia secunda subsp. obtusata (Turcz.) Böcher (Ericaceae), Utricularia ochroleuca R.W.Hartm. (Lentibulariaceae), Primula egaliksensis Wormsk. (Primulaceae), Coptidium × spitsbergense (Hadač) Luferov & Prob. (Ranunculaceae) and Salix fuscescens Anderss. (Salicaceae). In that paper, we also included our study area collections of Andromeda polifolia L. and Pinguicula vulgaris L.; we reported both as new in other parts of the Canadian Arctic Archipelago. We do not repeat the information Gillespie et al. (2015) provided for the new records, including summaries of Arctic distribution, taxonomic history and photographs. However, we cite all known voucher material for each taxon from the study area, including specimens Gillespie et al. (2015) cited.

Lycopodiales

Lycopodiaceae

Huperzia Bernh

Huperzia arctica (Grossh. ex Tolm.) Sipliv. (≡ H. selago subsp. arctica (Grossh. ex Tolm). Á.Löve & D.Löve, ≡ Lycopodium selago subsp. arcticum Grossh. ex Tolm.)—Arctic fir clubmoss | Circumpolar?

Previously recorded in Kimmirut as H. selago (L.) Bernh. ex Schrank & Mart. Widespread across Baffin Island and elsewhere on southern Baffin Island, recorded from Dorset and Mallik islands, Iqaluit, Jackman Sound (Potter 7407, GH 02077289) and Resolution Island (Aiken et al. 2007; Saarela et al. 2020a). Some H. arctica records, particularly from southern Arctic sites, may be H. continentalis; the specimens require review.

Kimmirut: Malte s.n. [118356] (CAN), s.n. [118358] (CAN), s.n./1198 [121040] (CAN, GH), Dutilly 1058 (CAN, QFA), 1063 (CAN) [KM-1].

Huperzia continentalis Testo, A.Haines & A.V.Gilman (Fig. 7A)—Continental firmoss | Amphi-Beringian–North American

Figure 7. 

A Huperzia continentalis habit, Saarela et al. 2054 B Spinulum annotinum habit, Saarela et al. 2131 C Juncus arcticus subsp. arcticus habit, Saarela et al. 2520 D Luzula spicata inflorescence (left) and habit (right), Saarela et al. 2014 E Luzula wahlenbergii inflorescence (left) and habit (right), Saarela et al. 1926 F Oreojuncus trifidus habit, Saarela et al. 2759 G Carex arctogena inflorescence (left) and habit (right), Saarela et al. 2349 H Carex chordorrhiza inflorescence (left) and habit (right), Saarela et al. 2182. Photos A, B by R.D. Bull, C–G by J.M. Saarela and H by P.C. Sokoloff.

Newly recorded from Kimmirut, the park, Pleasant Inlet and the study area. This recently described species (Testo et al. 2016) differs from H. arctica by leaf size, presentation and colour and gemmae size and shape, as described in the key below. Huperzia continentalis occurs throughout north-western and northern North America, including Greenland, and in northeast Asia and northwest Europe. In the Canadian Arctic, Testo et al. (2016) recorded it from the following sites: Northwest Territories: Hornaday River, Owen & Larsen 74-4011 (DAO) [Saarela et al. (2013) did not review this collection]. Nunavut: Coppermine [Kugluktuk], Findlay 258 (DAO) [Saarela et al. (2017) did not review this collection]; Canoe Lake, Peterson 21758 (DAO); Whale Point, Comer s.n. (GH); mainland near Depot Island, Comers s.n. (GH); Wager Bay area, Scotter & Zoltai 76140 (DAO); inland north of Wager Bay, Tremblay 085–2005 (DAO); Baffin Island, Tanner Bay, Elven 3503/99 (ALA); Baffin Island, Pangnirtung, Malte s.n. (GH); Coats Island, Porsild 5865 (GH). Northern Quebec: Richmond Gulf, mainland south of Cairn Island, Abbe & Abbe 3171 (GH); Monts de Puvirnituq, Tremblay 332–11 (DAO). Not all Huperzia material from Arctic Canada has been reviewed since the taxon’s description.

Katannilik Territorial Park: Aiken & Iles 02-059 (CAN) [CR-1], Saarela et al. 1999 (CAN, O) [MJ-20], 2054 (ALA, CAN) [MJ-17], 2318 (CAN, MT) [LR-15]. Kimmirut: Malte s.n./1168 [121010] (CAN, GH), Oldenburg 115 (MIN) [KM-1]. Pleasant Inlet: Saarela et al. 2722 (CAN) [PI-1].

Equisetales