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Vascular plants of Victoria Island (Northwest Territories and Nunavut, Canada): a specimen-based study of an Arctic flora
expand article infoJeffery M. Saarela, Paul C. Sokoloff, Lynn J. Gillespie, Roger D. Bull, Bruce A. Bennett§, Serguei Ponomarenko
‡ Canadian Museum of Nature, Ottawa, Canada
§ Unaffiliated, Whitehorse, Canada
Open Access

Abstract

Victoria Island in Canada’s western Arctic is the eighth largest island in the world and the second largest in Canada. Here, we report the results of a floristic study of vascular plant diversity of Victoria Island. The study is based on a specimen-based dataset comprising 7031 unique collections from the island, including some 2870 new collections gathered between 2008 and 2019 by the authors and nearly 1000 specimens variously gathered by N. Polunin (in 1947), M. Oldenburg (1940s–1950s) and S. Edlund (1980s) that, until recently, were part of the unprocessed backlog of the National Herbarium of Canada and unavailable to researchers. Results are presented in an annotated checklist, including keys and distribution maps for all taxa, citation of specimens, comments on taxonomy, distribution and the history of documentation of taxa across the island, and photographs for a subset of taxa. The vascular plant flora of Victoria Island comprises 38 families, 108 genera, 272 species, and 17 additional taxa. Of the 289 taxa known on the island, 237 are recorded from the Northwest Territories portion of the island and 277 from the Nunavut part. Thirty-nine taxa are known on the island from a single collection, seven from two collections and three from three collections. Twenty-one taxa in eight families are newly recorded for the flora of Victoria Island: Artemisia tilesii, Senecio lugens, Taraxacum scopulorum (Asteraceae); Crucihimalaya bursifolia, Draba fladnizensis, D. juvenilis, D. pilosa, D. simmonsii (Brassicaceae); Carex bigelowii subsp. bigelowii, Eriophorum russeolum subsp. albidum (Cyperaceae); Anthoxanthum monticola subsp. monticola, Bromus pumpellianus, Deschampsia cespitosa subsp. cespitosa, D. sukatschewii, Festuca rubra subsp. rubra, Lolium perenne, Poa pratensis subsp. pratensis (Poaceae); Stuckenia filiformis (Potamogetonaceae); Potentilla × prostrata (Rosaceae); Galium aparine (Rubiaceae); and Salix ovalifolia var. ovalifolia (Salicaceae). Eight of these are new to the flora of the Canadian Arctic Archipelago: Senecio lugens, Draba juvenilis, D. pilosa, Anthoxanthum monticola subsp. monticola, Bromus pumpellianus, Deschampsia cespitosa subsp. cespitosa, Poa pratensis subsp. pratensis and Salix ovalifolia var. ovalifolia. One of these, Galium aparine, is newly recorded for the flora of Nunavut. Four first records for Victoria Island are introduced plants discovered in Cambridge Bay in 2017: three grasses (Festuca rubra subsp. rubra, Lolium perenne, and Poa pratensis subsp. pratensis) and Galium aparine. One taxon, Juncus arcticus subsp. arcticus, is newly recorded from the Northwest Territories. Of the general areas on Victoria Island that have been botanically explored the most, the greatest diversity of vascular plants is recorded in Ulukhaktok (194 taxa) and the next most diverse area is Cambridge Bay (183 taxa). The floristic data presented here represent a new baseline on which continued exploration of the vascular flora of Victoria Island – particularly the numerous areas of the island that remain unexplored or poorly explored botanically – will build.

Keywords

biodiversity, Canadian Arctic Archipelago, checklist, floristics, herbarium, natural history collections, range extension, taxonomy

Introduction

The Canadian Arctic Archipelago is a large group of islands occupying the northern third of Canada and comprising 94 islands greater than 130 km2 and 36,469 smaller islands (Adams and Dunbar 2016). The Archipelago covers approximately 1.42 million km2. The Archipelago is fully within Inuit Nunangat, the Inuit homeland, a broader Arctic region encompassing approximately 35 percent of Canada’s landmass and 50 percent of its coastline.

The flora of an area (whether local, regional, national, continental or global) refers to all plant species and taxa at other ranks occurring in the area; it is a principal measure of biodiversity. Exploration and documentation of the vascular plant flora of the Canadian Arctic Archipelago has been ongoing since the earliest expeditions in search of the Northwest Passage, nearly 200 years ago, during which crew members obtained new scientific information on the natural history of the lands being explored, including collections of plants. Vascular plant specimens have accumulated from across the Archipelago through the decades, variously collected opportunistically or as part of botanical studies by both botanists and non-botanists alike. Many floristic studies of areas of the Canadian Arctic Archipelago have been published, ranging from simple lists of plants to more detailed accounts of plant biodiversity, including information about taxonomy, nomenclature, distribution and ecology (Polunin 1934, 1938b, a, 1939, 1940b, 1947, Cody 1951b, a, Brassard and Beschel 1968, Brassard and Longton 1970, Kuc 1970, Mason et al. 1972, Kuc 1974, Cody et al. 1976, Gillett 1976, Bridgland and Gillett 1983, Cody et al. 1984b, Soper and Powell 1985, Schwarzenbach 2010). Among the most important taxonomic treatments of (or relevant to) the vascular flora of the Canadian Arctic Archipelago published prior to the middle of the twentieth century are works by Brown (1823), Richardson and Brown (1823), Simmons (1906), Simmons (1913) and Polunin (1940a). Critical works published after 1950 are those by Porsild (Porsild 1955, 1957, 1964, Porsild and Cody 1980), most of which are regularly consulted today, and Aiken et al. (2007), the most recent comprehensive survey of the area. Gillespie et al. (2015) reported additions to the flora of the Canadian Arctic Archipelago, increasing the number of species and infraspecific taxa currently recorded from the region to 375. A recent synthesis of the taxonomy of the global Arctic flora has advanced our understanding of the Canadian Arctic flora in an international context (Elven et al. 2011).

In contrast to the flora of an area, which is based on presence or absence of species regardless of abundance, vegetation refers to assemblage(s) of plant species, often focused on or characterized by the subset of species that are dominant in ecological communities. Arctic vegetation is responding rapidly to the changing Arctic climate, which is warming at twice the rate of the rest of the planet (Anisimov et al. 2007). Elmendorf et al. (2012) identified several biome-wide trends in a global plot-based study of tundra vegetation response to warming, including increased canopy height of vascular plants and increased litter abundance. Shrubification, an increase in shrub biomass, cover and abundance of woody species in response to climate change, has been documented widely across the Arctic (Myers-Smith et al. 2011, Tremblay et al. 2012, Gerald et al. 2013) and decreases in species richness of vascular plants and lichens are associated with it in field studies (Pajunen et al. 2011, Fraser et al. 2014). Species distribution models also predict a decrease in species diversity with shrubification (Mod and Luoto 2016). Shrubification is thought to be responsible, at least in part, for Arctic greening, an increase in biomass and productivity in Arctic ecosystems that has been measured by satellite-derived Normalised Difference Vegetation Index (NDVI) (Pouliot et al. 2009, Bhatt et al. 2010, Gerald et al. 2013). Arctic browning (a decrease in greenness) (Epstein et al. 2015, Phoenix and Bjerke 2016, Lara et al. 2018) has also been documented in some Arctic areas, attributed to such phenomena as thermokarst development, tundra fire, anomalous weather such as extreme winter warming, and insect and fungal pathogen outbreaks (Phoenix and Bjerke 2016). Flowering times and seed dispersal of vascular plants in the Canadian Arctic are correlated with summer temperature, with considerable variation among taxa and geographical areas (Panchen and Gorelick 2017); a changing climate is likely to affect these critical stages of vascular plant life history. As Arctic vegetation changes over the next century as temperatures increase, the composition of the Arctic flora, including the subset of species that is a minor or insignificant component of Arctic vegetation, is likely to also change.

Many regions of the Canadian Arctic Archipelago remain underexplored or unexplored botanically, given the massive size of the region, the short window of opportunity for making field collections during Arctic summer, the small number of taxonomically trained and oriented Arctic botanists conducting field research, and the great logistical challenges and costs associated with accessing remote Arctic areas (Mallory et al. 2018). Given the rapidly changing Arctic climate, there is now increased urgency in advancing taxonomy-focused, specimen-based documentation of the current diversity and distribution of the Canadian Arctic vascular flora, in order to establish a baseline to which future changes in species- and infraspecies-level diversity and distribution can be compared. Such floristic data is foundational to many fields of study, including biogeography, taxonomy, terrestrial ecology, conservation, invasive species biology, and it contributes to basic understanding of Canada’s natural heritage. Specimen-based documentation–meaning that every report of a species is supported by a voucher specimen and associated collection data archived in a publically accessible and permanent collection (i.e., herbarium)–ensures that preserved material, which is part of the permanent scientific record, can be consulted, used and cited indefinitely, as necessary, by future researchers. Studying previously-collected material is a standard part of taxonomic practice, allowing workers to confirm or revise earlier identifications in light of misidentifications, which are common in herbaria (Goodwin et al. 2015), and changing taxonomic concepts through time, which are also common. The latter is exemplified by the “consensus” taxonomy proposed (except in a few cases in which a consensus was not achieved among authors from different geographical regions) for the circumpolar Arctic flora by Elven et al. (2011), which includes many taxonomic concepts that conflict with one or more regionally-accepted approaches to classification.

Here, we report the results of a collections-based floristic study of Victoria Island in the western Canadian Arctic Archipelago. Our study synthesizes existing published and unpublished information on the flora of the island, including new results from five field seasons (2008, 2010, 2013, 2014 and 2016) of botanical collecting at sites across the island. A small subset of collections from our 2008 and 2010 trips, representing first records of the following species for Victoria Island (or first records with confirmed vouchers), were reported in Gillespie et al. (2015): Carex bicolor, Eriophorum brachyantherum, Luzula wahlenbergii, Corallorhiza trifida, Puccinellia banksiensis, Stuckenia vaginata, Suaeda calceoliformis, Arenaria humifusa, Arenaria longipedunculata, Sabulina stricta, Andromeda polifolia, Oxytropis deflexa var. foliolosa, Pinguicula vulgaris and Salix arctophila. We present an annotated checklist of the vascular flora of Victoria Island in which we summarize the history of documentation of the flora and cite all specimens including new reports of first records for the island and many new records of species at sites across the island. We also provide taxonomic keys to identify all taxa currently recorded on the island, distribution maps for all taxa on the island, and photographs of many taxa. This work will serve as a new baseline on which continued floristic exploration of Victoria Island can build.

Victoria Island

Victoria Island (217, 291 km2), about 3.8% larger than Great Britain, is the eighth largest island in the world and the second largest (after Baffin Island, 507,451 km2) in Canada. It is located in the western Canadian Arctic Archipelago (Fig. 1), bordered by Banks Island to the northwest, from which it is divided by Prince of Wales Straight; the mainland of Nunavut to the south, divided by Dolphin and Union Strait, Coronation Gulf, Dease Strait and the western portion of Queen Maud Gulf; King William Island to the southeast, separated by Victoria Straight; Boothia Peninsula and Prince of Wales Island to the east and northeast, respectively, separated by McClintock Channel; and Melville Island to the north, separated by Parry Channel. Wollaston Peninsula on the southwest part of the island, the southeast part of the island, and Prince Albert Peninsula on the northwest part of the island, were initially given, by Europeans, the English names Wollaston Land (Franklin and Richardson 1828), Victoria Land (Simpson 1843) and Prince Albert Land (Belcher 1855), named for English chemist and physicist William Hyde Wollaston, Queen Victoria and Prince Albert, respectively. John Rae, in 1851, confirmed that Wollaston and Victoria lands were connected (Rae 1852a, b).

Figure 1. 

Map of Victoria Island showing locations of named places referred to in the current study. Inset: map of Canada showing the location of Victoria Island in the western Canadian Arctic Archipelago.

Victoria Island was part of British Arctic territory from the 16th century to 1880, the year the British Arctic Territories were claimed by Canada and became part of the Northwest Territories. It remained wholly part of that territory until creation of the territory of Nunavut in 1999. Victoria Island now spans the two territories. The territorial border corresponds to the boundary of the Inuvialuit Settlement Region, which includes much of the western third of the island. The Northwest Territories portion of the island comprises the northern half of the western tip of Wollaston Peninsula, land north of the 70th parallel north except for a southern protrusion around most of Quunnqug Lake, and land east of the 110th meridian west. The Northwest Territories portion of the island is part of the Inuvik Region, and the Nunavut portion is part of the Kitikmeot Region. Victoria Island has been inhabited since approximately 4500 BP (Savelle and Dyke 2002). Today, people live in the communities of Ulukhaktok (formerly Holman), located at the end of the Diamond Jenness Peninsula on the north side of the entrance to Prince Albert Sound on the west coast of the island, and Cambridge Bay (Iqaluktuutiaq), located on the southeast coast of the island along a bay of the same name.

Ecology

Victoria Island is fully within the Canadian Arctic ecozone, and of the three major Arctic regions recognized in Canada, it is part of the Northern Arctic, as is most of the Canadian Arctic Archipelago (Ecological Stratification Working Group 1995). In the global Köppen–Geiger climate classification, Victoria Island is part of the ET (polar tundra) group (Kottek et al. 2006). For the Arctic area including Victoria Island, climate model projections predict that, by 2071–2100, mean air temperatures could increase by up to 8 °C and the K-G classification of different parts of the island could shift to Semi-arid and subarctic climates (Beck et al. 2018). Such climate changes would likely be accompanied by a major shift in vascular plant species composition, reflecting the milder conditions. Vegetation studies have been conducted at a broad scale across the western half of the island (Edlund 1983) and at a fine a scale in the Wellington Bay area of southeastern Victoria Island (Schaefer and Messier 1994, Schaefer and Messier 1995). Peros and Gajewski (2008) reconstructed vegetation change during the Holocene using sediment-derived pollen data from a lake in the Kuujjua River area of the island, and found that herbaceous plants increased and woody plants decreased through the Holocene in response to long-term cooling; their pollen dataset also records a 0.5 °C increase in temperature over the last century.

The Circumpolar Arctic Vegetation Map–an international effort to develop a unified terminology for describing global Arctic vegetation–divides the circumpolar Arctic into five bioclimate zones (CAVM Team 2003, Walker et al. 2005). The zones are named A to E from north to south, with A, restricted in Canada to the northwestern Queen Elizabeth Islands, being the coldest and harshest, with a mean July temperature of 0–3 °C, <5% cover of vascular plants, vascular plant growth low to the ground (barely exceeding the height of mosses, woody plants absent), and less than 50 species in local floras, and E, restricted in Canada to the mainland, being the warmest and least harsh, with a mean July temperature of 9–12 °C, 80–100% cover of vascular plants, a herbaceous/dwarf-shrub layer 20–50(–80 cm) tall, and 200 to 500 species in local floras. Victoria Island spans bioclimate subzones D and C, reflecting the climatic gradient across the island (Fig. 2). Subzone C encompasses the southern and western portion of the island, with the boundary running from the southeast to northwest from approximately Macready Pt. to northwest of Hay Pt. Subzone C has a mean July temperature of 5–7 °C, a summer warmth index (i.e., sum of mean monthly temperatures greater than 0 °C) of 9–12, 5–50% cover of vascular plants, herbaceous layer 5–10 cm tall, prostrate and hemiprostrate dwarf shrubs less than 15 cm tall, and 75–150 species in local floras. Subzone D has a mean temperature of 7–9 °C, a summer warmth index of 12–20, 50–80% cover of vascular plants, herbaceous and dwarf shrub layers 10–40 cm tall, and 125–250 species in local floras. The Canadian High Arctic Research Station (CHARS) is currently leading a bioclimatic mapping of Victoria Island project. The goal of the project is to refine and better characterize previously determined boundaries between subzones C and D on the island based on results of fieldwork and aerial surveys.

Figure 2. 

Ecological zones recognized on Victoria Island. A Locations of bioclimate subzones C and D according to the Circumpolar Arctic Vegetation Map (CAVM Team 2003) B ecological regions recognized in the Northwest Territories part of Victoria Island by the Ecosystem Classification Group (2013). MA = Mid-Arctic. LAn = Low Arctic-north.

The two communities on Victoria Island are located within bioclimate subzone D. Cambridge Bay has a mean annual air temperature of -13.9 °C for the climate normal period of 1981–2010 and the mean annual temperature in July is 8.9 °C and in February is -32.5 °C for the same period (Environment Canada 2019a). Mean annual air temperatures in Cambridge Bay have increased by an average of 0.6 °C per decade over the 30 year period 1986–2015 with most warming occurring in fall and winter (BGC Engineering Inc. 2016). Average rainfall in Cambridge Bay is 72.1 mm, with the greatest average rainfall in July and August (23.9 mm in each). Average snowfall in Cambridge Bay is 80.2 cm, with the greatest average snowfall in October (15.9 cm). Ulukhaktok has a mean annual air temperature of -11.6 °C for the climate normal period of 1981–2010 and the mean annual temperature in July is 9.0 °C and in February is -28.8 °C (Environment Canada 2019b). Average rainfall in Ulukhaktok is 74.2 mm, with greatest average rainfall in July (22.2 mm) and August (30.2 mm). Average snowfall is 83.3 cm, with greatest average snowfall in October (16.9 cm).

The Northwest Territories Ecosystem Classification Group (2013) produced a detailed, multilevel ecosystem classification for the territory, including the Northwest Territories part of Victoria Island. The Level 1 (Tundra) and Level 2 (Northern Arctic) ecoregions of which Victoria Island is part are broad regional landscapes.They recognized two Level III ecoregions, which are interpretations of regional climates, on Victoria Island: Northern Arctic Mid-Arctic Ecoregion and Northern Arctic Low Arctic-north Ecoregion. Within the Northern Arctic Mid-Arctic Ecoregion they identified six Level IV ecoregions (Fig. 2), which are characterized by bedrock geology, landform, hydrology and vegetation: (1) the West Prince Albert Lowland Mid-Arctic Ecoregion, encompassing most of the Prince Albert Peninsula, composed of dry, calcareous, undulating to hummocky till and glaciofluvial deposits with sparse tundra cover on uplands and sedge tundra on seepage slopes; (2) the West Prince Albert Upland Mid-Arctic Ecoregion, in the middle of the northwestern arm of the Prince Albert Peninsula, comprising a low, discontinuous ridge with gravelly to clayey tills and variable tundra cover; (3) the East Prince Albert Plain Mid-Arctic Ecoregion, on the east side of Richard Collinson Inlet, a primarily frost-shattered calcareous bedrock plain with bouldery till and sparse to absent tundra cover; (4) the Shaler Mountains Mid-Arctic Ecoregion, extending northeast from Diamond Jenness Peninsula across the centre of Victoria Island to the tip of Natkusiak Peninsula, composed of deeply eroded bedrock ridges, plateaus and undulating stony till plains, with upland areas mostly sparsely vegetated and continuous tundra communities common on lower slopes and lowlands; (5) the Tahiryuak Upland Mid-Arctic Ecoregion, east of Prince Albert Sound and along the south side and the west end of Diamond Jenness Peninsula, with a high lake density between approximately 100–300 m above sea level, composed of dry, undulating to hummocky stony tills, marine silts and clays, and bedrock outcrops, with tundra best developed in moist depressions and on seepage slopes; (6) the Wollaston Peninsula Mid-Arctic Ecoregion, including that part of the Wollaston Peninsula that is part of the Northwest Territories, composed of a central level to hummocky till landscape with variable tundra cover surrounded by a thin belt of ancient and mostly unvegetated gravel beaches. Within the Northern Arctic Low Arctic-north Ecoregion they recognized the Prince Albert Coastlands Low Arctic-north Ecoregion, restricted to a narrow zone of coastal areas and protected valleys extending from the head of Prince Albert Sound, along the south side of Diamond Jenness Peninsula, around Minto Inlet to the north side of Walker Bay, and inland along the Kuujjua River. It is composed of fluvial and marine coastal plains, steep rock-walled inlets, plateau remnants and hummocky to undulating till, with pockets of vigorous shrub tundra in deep sheltered valleys. There is no comparable ecosystem classification available for the Nunavut part of Victoria Island.

With the establishment of the Canadian High Arctic Research Station (CHARS; Polar Knowledge Canada) in Cambridge Bay in 2015, new ecological research has been initiated on Victoria Island and the adjacent mainland, including long-term, experiment-based monitoring of the terrestrial ecosystem (McLennan 2017). Victoria Island is part of the CHARS Experimental and Reference Area (ERA), a large study area centred around the CHARS campus in Cambridge Bay, including island and mainland areas and the communities of Ulukhaktok, Kugluktuk, Cambridge Bay, Gjoa Haven, Taloyoak and Kugaaruk (POLAR Knowledge Canada 2019). The Canadian Arctic-Subarctic Biogeoclimatic Ecosystem Classification (CASBEC) initiative aims to develop a standardized approach to classifying, naming, and interpreting Arctic and Subarctic terrestrial ecological communities at a range of scales, based on plant associations (McLennan et al. 2018, Ponomarenko et al. 2019). Floristic and taxonomic data, such as that presented here for Victoria Island, underpins this type of research, and we expect that new data and specimens obtained during future ecosystem classification and related research on Victoria Island will contribute to advancing floristic knowledge of the island.

Geology

Detailed accounts of the glaciation, geomorphology and surficial geology of Victoria Island are given by Washburn (1947), Thorsteinsson and Tozer (1962) and Fyles (1963), from which the following description is summarized. Most of Victoria Island is underlain by dolomite, with some limestone, sandstone and shale, originating in the early Paleozoic. Substrates across the island are primarily calcareous. Precambrian rocks form a belt of rugged terrain–the Shaler Mountains–comprising sandstone, shale, siltstone limestone, dolomite and gypsum overlain by basaltic lava and agglomerate, located on north-central Victoria Island, trending north-easterly from Diamond Jenness Peninsula to Hadley Bay, encompassing much of Diamond Jenness Peninsula, and reaching an altitude of 655 m, the highest point on the island. Isolated outcrops of Precambrian sandstone and gabbro are also exposed on the Richardson Islands on the south side of the island and in the adjacent Johansen Bay area and from Wellington Bay north to Washburn Lake; for a map, see de Kemp et al. (2006). Granitic outcrops occupying a small area are recorded on the west side of Hadley Bay.

Victoria Island was overlain by the Laurentide ice sheet during the Wisconsin glaciation, and the post-glacial landscape of the lowlands is characterized by numerous glacial landforms, including drumlins, drumlinoid ridges, till plain, moraines, esker complexes, kame hills, abandoned river valleys and meltwater channels, and glacio-lacustrine deposits (clay and silts). Marine strand lines marking former post-glacial marine limits are conspicuous on the island; nearly half the island was, at one point, submerged. Other marine features in inland areas include marine shells, raised deltas, raised beach ridges, abandoned strand lines and marine sediments. Coastal parts of western Victoria Island are characterized by having large morainal belts that often reach heights of 30 m or higher. Morainal topography is particularly varied on Wollaston Peninsula, attaining maximum height at the summit of Mt. Bumpus. Morainal belts of eastern Victoria Island are much smaller. The island is further characterized by its abundant lakes and rivers, floodplain deposits, alluvial fans and deltas. Pingos are present on southeastern Victoria Island, particularly on Wollaston Peninsula.

Ovayok Territorial Park

Ovayok Territorial Park, the only protected area on Victoria Island and one of three territorial parks in the Kitikmeot Region of Nunavut, is located 15 km east of the community of Cambridge Bay (Fig. 3). The park is centered on Uvayuq (formerly Ovayuk/Mount Pelly), an esker reaching an altitude of more than 200 m above sea level. Uvayuq is the largest of three eskers in the area; the others are Amaaqtuq (“Baby Pelly”) and Uvayuruhiq (formerly Mount Lady Pelly), located northwest of the park between Greiner (Iqaluktuuttiaq) and Ferguson (Tahiryuaq) lakes. The park covers approximately 16 km2. Uvayuq was given its English name, Mount Pelly, by Thomas Simpson and Peter Warren Dease in 1839, honouring then-governor of the Hudson’s Bay Company, John Henry Pelly (Simpson 1843). Up to date botanical information for vascular plant diversity is available for few Arctic territorial (Saarela et al. 2017b) and national parks (Saarela et al. 2013). Botanical diversity has not been reported for Ovayok Territorial Park, although the area has been a popular place for collecting, given its prominence on the landscape in the Cambridge Bay area.

Figure 3. 

Location of Ovayok Territorial Park in the vicinity of Cambridge Bay on Victoria Island, Nunavut.

Previous botanical collecting on Victoria Island

19th century collections

The earliest botanical collections on Victoria Island were gathered during a four-year (1850–1854), two-ship (Enterprise and Investigator), British expedition in search of Sir John Franklin’s missing ships Erebus and Terror, and by John Rae in 1851. These collections are housed at the Royal Botanic Gardens Kew (K; herbarium acronyms follow Thiers (continuously updated)) and are summarized in Simmons’ (1913) account of the early history of botanical exploration of the Canadian Arctic islands. Travelling aboard Investigator, commanded by Robert McClure, Moravian missionary and interpreter Johan A. Miertsching made five collections along Prince Albert Sound (Draba hirta L. [=D. glabella], Saxifraga oppositifolia, Potentilla rubricaulis, Astragalus aboriginorum Richardson [=A. richardsonii], Arctostaphylos alpina [=Arctous alpina]), and a collection of Salix arctica, taken at “Mount Adventure” [Adventure Mountain] on Prince Albert Peninsula, is attributed to McClure (Simmons 1913). Enterprise, commanded by Richard Collinson, was separated from Investigator in the Pacific, but eventually reached the western Arctic. The surgeon, Charles Anderson, who was among the crew on Enterprise, made botanical collections at Minto Inlet and Cambridge Bay, representing 94 species according to Simmons (1913) (Suppl. material 1). A collection of Oxyria digyna from Walker Bay, taken by Collinson, is also recorded by Simmons (1913).

John Rae made collections along the “south shore” of Victoria Island in 1851 while exploring and mapping the area (Rae and McGoogan 2012). He travelled to the island from the mainland twice that year. On 5 May, Rae crossed, by sledge, the frozen Dolphin and Union Straight and reached Douglas Island (68°28'N, 113°29'W), just west of Wollaston Land, the next day. Rae then travelled eastwards along the southern shore of Victoria Island as far as Wilbank Bay (68°38'N, 110°10'W). Upon his return to Douglas Island, on 15 May, he travelled northwards along the west coast of Wollaston Land to ca. 14 miles beyond Cape Baring (70°02'17"N, 117°21'33"W), before turning around. He returned to the mainland on 2 June. On the second leg of the 1851 expedition, Rae travelled by boat. He left the mouth of the Coppermine River in early July and travelled eastwards along the south shore of Coronation Gulf to the east end of Kent Peninsula. On 27 July he crossed the strait to Victoria Island, reaching Cambridge Bay. Leaving the bay, Rae followed the coast eastwards to Albert Edward Bay, and then travelled north overland on foot to a point ca. seven miles south of Pelly Point (70°12'N, 101°01'W) on the Collinson Peninsula, before turning around. On the return trip Rae apparently followed the southern coast of Victoria Island, as he describes stopping north-east of Cape Peel (69°02'30"N, 107°16'15"W) along Dease Strait and Point Ross [Ross Point; 68°31'N, 111°10'0"W) at Johansen Bay, which was reached on 28 August 1851. We are not aware of information as to precise localities of Rae’s botanical collections; there is no mention of them in his account of his travels on Victoria Island (Rae and McGoogan 2012). Given that his travels on the southwestern portion of the island occurred in May, when there would have been snow on the ground and conditions would not have been suitable for collecting plants, we assume that his collections were gathered on the “south shore” of the southeastern part of the island during July and August. Hooker (1856) listed Rae’s 1851 collections from Victoria Island and from the adjacent mainland, but he did not indicate in the list which specimens were from the island. Simmons (1913), having reviewed the collections at K, reported that Rae made 34 collections on Victoria Island (Suppl. material 1). These collections are also summarized in Porsild (1955).

20th century collections

A substantial amount of information on the flora of Victoria Island accumulated in the 20th century. The herbaria in which the collections described below are housed are listed in the Annotated Checklist, unless otherwise indicated. Diamond Jenness, anthropologist, made collections on “Wollaston Land” (Wollaston Peninsula) in 1915, during the Canadian Arctic Expedition, 1913–1918. These were reported in Macoun and Holm (1921). A list of 41 plant collections made by Jenness on the island was also included in Jenness (1991).

Considerable plant exploration of Victoria Island occurred in the 1940s, when many plant collections were made at fur trading posts on the eastern shore of Walker Bay (Fort Collinson), at Holman and Cambridge Bay, and on Read Island just off the south coast of the Wollaston Peninsula. Father Arthème Dutilly, associated with the Catholic University of America, collected in 1940 at Holman, at a site referred to on his collection labels as “Willows Patch” [Boot Inlet; see comments under Salix alaxensis about the location of this site], at Kookyoak River [=Kuujjua R.] and at Cambridge Bay (Louis-Marie 1961). Dutilly’s collections are distributed widely in herbaria in Canada, the United States and Europe (Boivin 1983). Although collected over 70 years ago, most of Dutilly’s Victoria Island collections were not included in the distribution maps in Arctic floristic treatments that include the island (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). The geologist Albert L. Washburn made collections at Cambridge Bay in 1940. In 1941 and 1942, Lillian Ross, spouse of trading post manager Ray Ross, collected at Holman Island post, Read Island post and sites on southern Victoria Island adjacent to Read Island. In 1947, the geologist Y.O. Fortier made collections at Greely Haven (1 August) and Cambridge Bay (3 August). Also in 1947, Nicholas Polunin, Oxford University, made collections at Cambridge Bay (24 August); these collections have not previously been accessible for research, being part of the unprocessed backlog of the National Herbarium of Canada (CAN). In 1948, John L. (Pete) Jenness, son of Diamond Jenness, made a few collections in the vicinity of Richard Collinson Inlet and on the Storkerson Peninsula.

Botanist A. Erling Porsild, with the National Museum of Canada, collected on Victoria Island in 1949 at several sites, spending no more than two days at each: Read Island (27 July), the interior of the Wollaston Peninsula (27 July), the head of Prince Albert Sound (4 August), Holman Island (Ulukhaktok; 8 August), “Jackpot Lake” (an unnamed lake east of the head of Minto Inlet; 16 August), Walker Bay (at Fort Collinson; 25 August), the head of Minto Inlet (2–3 August), Cambridge Bay (5 August), an unnamed lake ca. 60 miles north of Cambridge Bay (6 August), Tahoe Lake and Washburn Lake (4 August), and a few other places inland. Those collections reportedly doubled the number of species known from the island, bringing the then-known flora to 201 species (Porsild 1950a). The collections were reported in Porsild (1955), a monograph on vascular plants of the Western Canadian Arctic Archipelago, including Axel Heiberg, Amund Ringnes, Ellef Ringnes, Borden, Mackenzie King, Cornwallis, Bathurst, Prince Patrick, Melville, Banks, Victoria, Prince of Wales, and King William islands, and numerous smaller islands. Porsild returned to Cambridge Bay in 1959 and again collected there (12 August).

Margaret Oldenburg, an amateur botanist from Grand Marais, Minnesota, travelled and botanized extensively across Victoria Island in the 1940s and 1950s. She travelled primarily by chartered aircraft, typically collecting during brief stops. In 1943, she made collections at Holman Island (=Ulukhaktok; 1 August) and Read Island (23–24, 31 August, 2–3 September). In 1944, she collected at Cambridge Bay (14–15 August) and again at Read Island (20 August). In 1945, she collected at Ulukhaktok (12 August), Walker Bay (12 August) and “Oldenburg Lake” (11 August), an unnamed lake on northwestern Victoria Island west of Peel Point. We determined the location of “Oldenburg Lake” (73.11750, -114.58) based on information in Whyard (1984). In 1946, she collected on the north side of Prince Albert Sound (19 August). In 1954, she collected at “Char Lake” (15 August), which is a small lake southwest of the head of Richard Collinson Inlet on the Prince Albert Peninsula, “Yellow Lake” (8–9 August), which is an inland site east of Deans Dundas Bay, and on a pingo on northwestern Wollaston Peninsula (16 August). We determined the locations of “Char Lake”, “Yellow Lake” and the pingo based on maps on Oldenburg’s specimen labels, on which the sites are mapped as “Sta. 20” [station 20], “Sta. 10” and “Sta. 21”, respectively. Presence of pingos in the area indicated by Oldenburg is confirmed by Geological Survey of Canada (2017). Despite the importance of Oldenburg’s collections, which are extensive and, in many cases, represent the first (and in some cases only) collections from sites on the island, they were not considered in earlier Arctic floristic works. They were, however, known to Porsild (1955) as being unnamed and inaccessible in the Herbarium of the University of Minnesota (MIN). A subset of Oldenburg’s collections from Victoria Island are housed at GH, MIN and UBC, but the majority were recently “discovered”, along with her collections from other Arctic and non-Arctic sites, in the unprocessed backlog cabinets of the National Herbarium of Canada.

Botanical documentation of the Victoria Island flora continued through the 1950s. Entomologists E. Smith and D.K. Sweatman, Department of Agriculture, Ottawa, collected in 1950 at Holman Island (Ulukhaktok). In 1952, entomologists D.P. Gray and B. Gibbard, also with the Dept. of Agriculture, made collections at Holman Island (Ulukhaktok). In 1959 and 1960, W.D. Stretton, Army Survey Establishment, made collections at Cambridge Bay and at numerous sites in interior Victoria Island, during defence mapping operations. Areas where Stretton collected include the north side and head of Prince Albert Sound, Berkeley Point, Burns Lake, Freshwater Bay, Gordon Point, Kuujjua River, Murray Point, Richard Collinson Inlet, Storkerson Peninsula, Ulukhaktok and the west end of the Diamond Jenness Peninsula. Botanists J.A. Calder, D.B.O. Savile and I. Kukkonen collected at Cambridge Bay on 12 August 1959.

Collections in the 1960s were focused on southeastern Victoria Island and in the 1970s in the Ulukhaktok area. Homer A. “Steve” Stephens (and his associate George M. Sutton) made extensive collections in 1962 in the vicinities of Cambridge Bay and Mount Pelly, in association with research on the White-rumped Sandpiper at Cambridge Bay. Stephens also made collections on Jenny Lind Island immediately southeast of Victoria Island in Queen Maud Gulf (Sutton 1967, Parmelee et al. 1968), which are not considered here. In the same year, Robert Hainault made collections at Mt. Pelly, Mt. Lady Pelly and Ferguson Lake north of Cambridge Bay. Ecologist Josef Svoboda, University of Toronto, made collections at Holman (Ulukhaktok) in 1974. Ecologist Lawrence C. Bliss, University of Alberta, collected there that same year.

In the 1980s, Sylvia A. Edlund, Geological Survey of Canada, made substantial contributions to knowledge of the flora of Victoria Island, associated with research characterizing the relationships between surficial geology and plant communities. She made more than 1800 collections at numerous sites across the island, including many from sites where no other collections have been made. Sites visited and collected by Edlund in 1982 include Armstrong Point, Boot Inlet, Cape Baring, Cape Wollaston, Kugaluk River, Kuujjua River, the head of Minto Inlet, Mt. Bumpus, Murray Point, Natkusiak Peninsula, Peel Point, the north side and head of Prince Albert Sound, Richard Collinson Inlet, Sangraun Hills, Shaler Mountains near Richard Collinson Inlet, Tahiryuaq (a large lake north of the head of Prince Albert Sound), Ulukhaktok and southwestern Wollaston Peninsula (Edlund 1983). In 1983, Edlund collected at Cambridge Bay and the head of Minto Inlet, and in 1986 at Hadley Bay and Storkerson Peninsula on northeastern Victoria Island. Edlund collected in 1987 with salicologist George Argus (National Museum of Canada) at Albert Edward Bay, Anderson Bay, Byron Bay, Cambridge Bay and vicinity (including “Starvation Cove”), Cape Colborne, Collinson Peninsula, Diamond Jenness Peninsula, Ferguson Lake, Greiner Lake, Jonnessee Lake, Namaycush Lake, the head of Prince Albert Sound, Surrey Lake and Washburn Lake. Other sites visited in 1987 (without Argus listed as a collector) include the vicinities of Burns Lake, Cape Peel and Namaycush Lake. Edlund’s vouchers are deposited in the National Herbarium of Canada; most are unicates. None of Edlund’s collections have been published, but many were mapped in Aiken et al. (2007). Some 322 of Edlund’s Victoria Island collections, however, were not included in Aiken et al. (2007), as the material was, at the time, part of the unmounted backlog in the National Herbarium of Canada and inaccessible for research.

Botanical exploration of Victoria Island continued in the 1990s. William T. Dushenko made collections at Byron Bay in 1992, in association with research on environmental contaminants (Dushenko et al. 1996). In 1993, Anne H. Weerstra made collections in the Kagloryuak River valley east of the head of Prince Albert Sound, during field research on the breeding biology of the King Eider. Botanist Lynn J. Gillespie, Canadian Museum of Nature, collected in the vicinity of Cambridge Bay in August 1994, and again with Laurie L. Consaul, Canadian Museum of Nature, in July 1997. In 1999, William A. Gould, International Institute of Tropical Forestry, Puerto Rico, made collections at Cambridge Bay, Mt. Pelly, Hadley Bay and along the Tuktu River on central Victoria Island during fieldwork associated with the Circumpolar Arctic Vegetation Map project (Gould et al. 2003). In the same year, Carolyn L. Parker made collections in the vicinity of Cambridge Bay, and Bente Eriksen, Esther Levesque and C.L. Parker made collections in the vicinity of Falaise Bay on Wollaston Peninsula, as part of the Tundra Northwest Expedition 1999 (Eriksen et al. 2006). In 2003 and 2004, collections were made at Ulukhaktok by Robert Bandringa in association with ethnobotanical work (Bandringa et al. 2010).

Over three decades, ecologist Dietbert Thannheiser, University of Hamburg, Germany, conducted phytosociological research at sites on Victoria Island, including Cambridge Bay (1983, 1984, 1986, 1987, 1998), Holman (Ulukhaktok; 1986, 1973), the head of Minto Inlet (1986), Mt. Pelly (1984), Wellington Bay (1983), Hadley Bay (1986), Surrey Lake, Richardson Islands and Johansen Bay (Thannheiser 1986, Thannheiser et al. 2001). Thannheiser et al. (2001) published a list of species occurrences for each of these regions, including numerous first records for Victoria Island. No vouchers are cited, but the paper indicates that vouchers are in personal herbaria of the authors; most or all are now housed in the herbarium of The Arctic University of Norway​ (TROM) but were not examined here. It is unclear, however, if all, or only a subset of material, is vouchered. Some records reported in that paper were considered in Gillespie et al. (2015), but none were considered in Aiken et al. (2007) nor, to our knowledge, in other taxonomic works.

Despite over a century of exploration and documentation of the vascular flora of Victoria Island, only a small subset of the collection data has been published in detail. Material gathered on the island during the Canadian Arctic Expedition was published by Macoun and Holm (1921). Porsild (1955) included voucher information for Victoria Island collections known to him at the time, including details of the collections he made on the island in 1949. It is relatively straightforward to align records reported by Porsild (1955) to maps published in his later treatments (Porsild 1957, 1964, Porsild and Cody 1980), but for collections that were not cited in Porsild (1955), substantial effort is needed to match dots on distribution maps in floristic or taxonomic treatments with vouchers. None of the critical Arctic treatments that cover Victoria Island (Porsild 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007) include details of the specimens on which the works are based. In many instances, Porsild (1955) noted unvouchered observations of species occurrences made by him in 1949, and he included these site records on his subsequent maps without any indication that they are based on unvouchered reports (Porsild 1957, 1964, Porsild and Cody 1980). Aiken et al. (2007) mapped many thousands of records using digital tools but did not publish the dataset underlying the distribution maps. The large dots on the maps in that treatment each cover ca. 40 km, making it difficult or impossible, in some cases, to align a dot to a particular voucher specimen or area, especially in areas where numerous collections have been made, such as in the Cambridge Bay region.

Materials and methods

Field work

2008, 2010 and 2017

In July 2008, our team, comprising L.J. Gillespie, J.M. Saarela, L.L. Consaul and R.D. Bull (Canadian Museum of Nature), explored and collected plants along southern Victoria Island, Nunavut. Research was carried out under Nunavut Research Institute Scientific Research Licence 0401308N-A, Nunavut Wildlife Research Permit No. WL 2008-1039, Nunavut Water Board Permit No. 3BC-AFP0813 and Polar Continental Shelf Program (PCSP) Project Number 515-08. We established three base camps: (1) at a site ca. 13 km north of Oterkvik Point and 10 km north of the coast at Coronation Gulf (68°36'50"N, 112°34'21"W; 3–11 July); (2) 8 km east-northeast of Johansen Bay airstrip along the Nakoyoktok River at its outflow from a large unnamed lake (68°39'25"N, 110°42'30"W; 12–21 July); and (3) Sinclair Creek North Warning System site (abandoned DEW-line site) (68°45'5"N, 109°06'20"W; 22–24 July). In each area, we explored as many habitats as possible, by foot, at each camp, and made collections as we encountered taxa. Our aim was to document all of the vascular plant species in the vicinity of each of our three camps with at least one voucher specimen. We also explored several remote sites accessed by helicopter. Staging from Oterkvik Point, we visited five sites via helicopter on 7 July: two sites along a bay on Coronation Gulf east of Oterkvik Point (68°30'46"N, 112°33'60"W; 68°29'17"N, 112°40'13"W); an esker ca. 21 km north of the coast at Coronation Gulf and 24 km north-northeast of Oterkvik Point (68°41'59"N, 112°26'23"W); a low rocky ridge between two lakes near the previous locality (68°42'48"N, 112°30'08"W); low rocky hills at the coast in the vicinity of Oterkvik Point (68°31'32"N, 111°59'58"W; longitude coordinates recorded on specimen labels for this site as 112°59'58"W are erroneous). Collections made while exploring the Oterkvik Point area on foot and during the five helicopter stops noted above are recorded in the annotated checklist as being from Oterkvik Pt. Staging from Oterkvik Point, we also visited two more distant sites via helicopter on 8 July: the eastern-most slopes of the Colville Mountains (69°32'45"N, 112°41'27"W) and the vicinity of a river flowing into Clouston Bay, 3–4 km from the river mouth (69°02'39"N, 113°25'15"W). These are treated as separate sites in the annotated checklist. Staging from Johansen Bay we visited five sites via helicopter on 20 July: a flat-topped steep-sided hill, 11 km northeast of the Johansen Bay airstrip (68°39'12"N, 110°54'47"W); a pingo 23 km west of the Johansen Bay airstrip (68°26'23"N, 111°40'22"W); the Johansen Bay airstrip (68°35'50"N, 111°6'59"W); the west end of Johansen Bay at the mouth of Mackenzie Creek (68°36'4"N, 111°21'7"W); and Mackenzie Creek, about 1 km from its mouth at the west end of Johansen Bay, along a river canyon above a waterfall and rapids (68°36'28"N, 111°22'10"W). Collections made while exploring the Johansen Bay area on foot and during the five helicopter stops noted above are recorded in the annotated checklist as being from Johansen Bay. Staging from Sinclair Cr., we visited one site via helicopter on 21 July: Murray Point on the west side of Wilbank Bay (68°35'33.5"N, 110°18'24"W). Murray Point is treated as a separate site in the annotated checklist. In total we made 1091 collections (numbers) of vascular plants, one of lichens and 27 of bryophytes.

In July 2010, we conducted fieldwork on northwestern Victoria Island, Northwest Territories, again aiming to document all species present at each site visited. Our team comprised L.J. Gillespie, J.M. Saarela, Jennifer Doubt, R.D. Bull and P.C. Sokoloff (Canadian Museum of Nature). Research was carried out under Aurora Research Institute Licence No. 14733, Inuvialuit Land Administration Licence No. ILA10HN004, and PCSP Project Number 509-10. We established three base camps: (1) at a site ca. 8 km inland from the head of Minto Inlet adjacent to a Geo-Mapping for Energy and Minerals (GEM) program, Natural Resources Canada, camp (71°37'10"N, 115°26'22"W; 7–8, 19–26 July); (2) at a site on the northeast side of a small round unnamed lake (ca. 1 km diameter) ca. 4 km north of Boot Inlet on the north side of Minto Inlet (71°30'35"N, 117°20'35"W; 9–12 July); and (3) at a site on the southeast side of “Fish Lake” on the lower Kuujjua River between two small lakes, on the south side of Minto Inlet (71°12'28"N, 116°22'46"W; 12–18 July). Collections were also made in Ulukhaktok by J.M. Saarela and R.D. Bull (5–6 July; Saarela nos. 1410–1508). Staging from the Kuujjua River camp we visited three sites by helicopter on 17 July: the base of north-facing cliffs 68 km east-northeast of Ulukhaktok (71°2'60"N, 116°9'48"W); the sandy banks of the Kuujjua River south of “Fish Lake”, ca. 17 km southeast of the head of Minto Inlet (71°6'43"N, 116°6'21"W); the shore of the Kuujjua River delta at Minto Inlet (71°15'23"N, 116°49'35"W). Staging from the Minto Inlet camp we visited three sites via helicopter on 25 July: a deep canyon on an escarpment south of the head of Minto Inlet in the vicinity of large waterfall (71°25'30"N, 115°12'2"W), a coastal saline flat along the end of the eastern most inlet (north arm) at the head of Minto Inlet (71°31'7"N, 115°6'30"W), and an esker on a plain 3 km south of the head of Minto Inlet (71°27'10"N, 115°17'3"W). We made 1048 collections (numbers) of vascular plants, one of lichens, five of bryophytes and 14 of fungi. Jennifer Doubt made extensive collections of bryophytes during this expedition, which are not considered here.

In 2017, 20 collections were made in Cambridge Bay by J.M. Saarela (nos. 5296–5301) during the Canada C3 expedition (https://canadac3.ca/en/homepage/).

All 2008, 2010 and 2017 collections were dried in the field in standard plant presses. For each collection we preserved a small sample of leaf tissue in silica gel for future molecular analyses. In most cases, we tagged the plant from which we obtained the sample. These tissue samples are preserved in the National Biodiversity Cryobank of Canada at the Canadian Museum of Nature. These collections were variously determined by L.J. Gillespie, J.M. Saarela and P.C. Sokoloff unless otherwise indicated (Suppl. material 2). Willows were identified by George Argus (CAN). A subset of our Draba, Papaver and Potentilla collections were determined by R. Elven and confirmed by us. The first set of our collections is deposited in the National Herbarium of Canada (CAN), Canadian Museum of Nature. Duplicate specimens have been distributed to the following herbaria, as noted in the specimen citations and Suppl. material 2: University of Alaska Museum of the North (ALA); Aurora Research Institute, Inuvik (indicated in the annotated checklist as “ari”, as the herbarium does not have an official acronym); the University of Alberta Vascular Plant Herbarium (ALTA); Icelandic Institute of Natural History, Akureyri Division (AMNH); the B.A. Bennett Herbarium (BABY), Yukon; the Botanical Museum in Oslo (O); the Missouri Botanical Garden (MO); the Marie-Victorin Herbarium (MT), University of Montreal; the Ayre Herbarium (NFLD), Memorial University of Newfoundland; the herbarium in the Beaty Biodiversity Museum (UBC) Beaty Biodiversity Museum; the United States National Herbarium (US), National Museum of Natural History, Smithsonian Institution; the Intermountain Herbarium (UTC), Utah State University; the Royal British Columbia Museum (V); the University of Manitoba Herbarium (WIN); and the herbarium of the Institut für Systematische Botanik (Z), Universität Zürich.

2013, 2014

Fieldwork was conducted by B.A. Bennett in the vicinity of Cambridge Bay in 2013 and the Cambridge Bay and broader vicinity in 2014. The aim of this work was to document all species of vascular plants in the area to contribute to understanding of the ecology of the greater Canadian High Arctic Research Station (CHARS) (Polar Knowledge Canada) research area. In 2013, collections were made at numerous sites within the community, along the road to Mt. Pelly, within Ovayok Territorial Park, at the east end of Greiner Lake, and along the road west of the community, as far west as the hills above Long Point. In 2014, collections were made within the hamlet, across the bay from the hamlet, north of the DEW line site, at Long Point and at three sites more distant from the hamlet: “30-Mile Creek”, near the Ekalluk River and the west end of Ferguson Lake, and “Trunsky Lake”. Vouchers of material collected in 2014 has been distributed to ALA, BABY, CAN, MO, UBC, V as well as the CHARS herbarium (indicated in the annotated checklist as “chars”, as the herbarium does not have an official acronym) in Cambridge Bay; Stanley L. Welsh Herbarium (BRY), Brigham Young University; National Collection of Vascular Plants (DAO), Agriculture and Agri-Food Canada, Ottawa; Herbarium (MICH), University of Michigan; Michael J. Oldham herbarium, Peterborough, Ontario (indicated in the annotated checklist as “od”, as the herbarium does not have an official acronym); Herbarium (SRP), Boise State University; Herbarium (UAAH), University of Alaska Anchorage; and Herbarium (WTU), University of Washington. We here consider 319 collections made by B. Bennett and associates in 2013 and 2014.

2016, 2018 and 2019

Botanical fieldwork was conducted by CHARS ecologist S. Ponomarenko during three field seasons. From 3–18 August 2016 a vegetation survey was carried out for the CHARS Intensive Monitoring Area (IMA), an area restricted to two small watersheds within the Greiner Lake watershed that drains to the northern shore of Greiner Lake approximately 20–30 km to the northeast of Cambridge Bay, an area measuring about 50 km2. This work was conducted as part of the high resolution vegetation mapping of the CHARS IMA project (Ponomarenko et al. 2019).

In the 2018 and 2019 field seasons, floristic collections were obtained during helicopters surveys of a broader area. In 2018, five days of helicopter surveys were undertaken within the Greiner Lake watershed, an area measuring approximately 1,500 km2. In 2019, eight days of helicopter surveys were undertaken north and east of Greiner Lake watershed along the border of bioclimatic subzones C and D. This survey covered an area of about 2,000 km2 north and east from the Greiner Lake watershed. This work constituted a part of the vegetation inventory and mapping project aiming to assemble baseline data for the CHARS ERA.

Vouchers collected during these three years of fieldwork are housed at CAN and CHARS. In total more than 700 specimens were collected, of which 394 collections were reviewed for this work. The remaining 300 collections, mainly collected in 2019, are not yet processed.

Herbarium research and data curation

In addition to accounting for our new collections, we attempted to locate and confirm or revise determinations of all unique collections of vascular plants from Victoria Island. To find specimens collected previously from the study area, we manually searched the collections at CAN, DAO, MT, the University of Calgary (UAC), UBC and Herbier Louis-Marie (QFA), Université Laval, and we queried the Global Biodiversity Information Facility (GBIF), Canadensys (http://data.canadensys.net/explorer/en/search), the Consortium of Pacific Northwest Herbaria (http://www.pnwherbaria.org/about.php), Integrated Digitized Biocollections (iDigBio) portal (https://www.idigbio.org/portal/search), and various institutional online databases. In addition to the herbaria noted above, specimens from Victoria Island cited here are deposited in the R.L. McGregor Herbarium (KANU), University of Kansas; H.A. Stephens Herbarium (KSTC), Emporia State University; TRTE Herbarium (TRTE), University of Toronto Mississauga; Herbier du Québec (QUE), Sainte-Foy, Québec; and Harvard University Herbaria (GH). We also reviewed relevant taxonomic and floristic literature (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007), conducted online searches, and consulted an unpublished database of specimen records that was developed and used in production of the "Flora of the Canadian Arctic Archipelago" (Aiken et al. 2007). We have seen and confirmed at least one duplicate for most of the specimens cited. A subset of material was confirmed based on review of specimen images available online. Determinations for some specimens we have not seen are accepted based on the authority of previous determiners, especially for taxa that are well known and not taxonomically problematic. We have also accepted some non-confirmed records from well-collected sites for which we have reviewed and confirmed numerous other records, such that a possible mis-identification of one of many records of a species from a site would not affect understanding of diversity at the site. With a few exceptions, we did not study the 19th century collections, for which site information is vague.

As part of the current study, three batches of unprocessed material gathered on Victoria Island in the 1940s, 1940s–50s and 1980s that was stored in the backlog collection of the National Herbarium of Canada were organized, identified, mounted and inserted into the permanent collection. One batch comprised 134 sheets collected by Nicholas Polunin at Cambridge Bay in 1947. The second batch comprised 498 sheets collected by Margaret Oldenburg at various sites across the island (see Introduction). The third batch comprised 359 collections gathered by Sylvia Edlund at various sites across the island in 1982, 1986 and 1987 (see Introduction). In the course of processing this material, we discovered that 38 of these Edlund backlog collections from Victoria Island had previously been assigned CAN accession numbers and were recorded in the museum database (and thus mobilized online), but the material remained unmounted, until now. These 991 collections–of which some were gathered 70+ years ago – are now available to the scientific community and are published here. The backlog material from Victoria Island dealt with here is a subset of larger backlog batches of Arctic specimens at CAN gathered by Edlund, Oldenburg and Polunin.

During the course of this study, imaging of all vascular plant material housed at CAN from Yukon, Northwest Territories and Nunavut was completed and all images were linked to the institutional database and mobilized via GBIF. GBIF tools were used to identify and fix putative data errors in Victoria Island records. The images also facilitated completion of data entry for CAN specimens from Victoria Island for which only “skeletal” records existed (i.e., taxon name and higher-level geographic provenance – country and province/territory) or for which data entry was otherwise incomplete.

We amalgamated all collection data obtained from different resources into a spreadsheet. Substantial manual cleaning of the complete dataset was undertaken to make the dataset useable, including standardizing names of collectors, date format and locality descriptions among specimens gathered by the same collector at the same site. We combined records of duplicate specimens housed in different collections into single records, maintaining information on the disposition(s) of the duplicate specimens.

We spent considerable time improving the georeferencing of records in our dataset. Most collections from Victoria Island were made long before the existence of the Global Positioning System and many before the existence of detailed topographical maps, or of maps, period. As such, many collections either lacked coordinates or included the following: (1) inaccurate or erroneous primary coordinates, (2) accurate or inaccurate secondary coordinates but no attribution or source information for the georeferenced coordinates, or (3) accurate but imprecise coordinates determined to the nearest minute, being within ca. one nautical mile of the site, assuming the coordinates are correct. Prior to the advent of digital mapping, this level of precision was generally sufficient for dot-based distribution maps presented at a fixed scale. For example, each dot in the maps in Porsild and Cody (1980) covers about 110 km across (ca. 9,503 km2) and in Aiken et al. (2007) about 40 km across (ca. 1,256 km2). In digital environments, however, inaccurate coordinates may be problematic and misleading. For many Victoria Island collections, imprecise label coordinates often placed terrestrial collecting sites in freshwater or marine environments or far from descriptions of the places where collections were made, well beyond distances likely to have been travelled by earlier collectors by foot in the limited time that was typically available for collecting at a site.

Therefore, to improve accuracy of geographical coordinates, we secondarily georeferenced many sites following standard point-radius protocols, including determining estimates of coordinate uncertainty in metres, in cases where we were confident that existing location data could be improved upon. Georeferencing was done by J.M. Saarela and Paul Wise, Canadian Museum of Nature. Georeferencing data is included in Suppl. material 2. Where possible, we refined georeferencing data through consultation of published information about the itineraries of past collectors. We also attempted to standardize georeferencing data for collections made in the same area by the same collectors at the same time and by different collectors at different times. At times, this required superseding previous georeferencing for a site. For example, many collections over several decades have been made at “Cambridge Bay”, and that area has been georeferenced differently many times by different workers at different herbaria, including georeferencing the hamlet and the bay, which both have the same name even though it is safe to assume that collections were made on land in the vicinity of the hamlet, not in the bay (a marine environment). The name “Holman Island” on labels has also been the cause of confusion. The hamlet of Ulukhaktok, the Kangiryuarmiutun name for the area, was until 2006 known as Holman and sometimes referred to as Holman Island, as it is on many early herbarium collections. Holman Island is also the name of a small island in the Amundsen Gulf to the east-southeast of Ulukhaktok, after which the community was originally named. Holman Island was named for John R. Holman, a member of the Inglefield Arctic Expedition (1853–54). Although contemporary workers have regularly confused the two places when georeferencing, we are not aware of any botanical collections from the true Holman Island (70°39'6"N, 117°43'33"W), and we have corrected those errors. Collections made at Holman or “vicinity of Holman Post [trading post]” up to 1966 were gathered on the east side of Kings Bay, the site of the community until it moved across the bay to its current location on Queen’s Bay in that year. All collections from the community now known as Ulukhaktok are included under that name.

Distribution maps were generated in ArcMap 10.5.1. Additionally, using ArcMap 10.5.1, we generated maps showing the locations of all collecting sites on the island, maps showing the locations of collections made by S. Edlund, including for specimens previously accessioned into the CAN herbarium and for specimens that had been housed in backlog and were newly accessioned as part of this study, and collections made by A.E. Porsild, Gillespie et al., B. Bennett, S. Ponomarenko, and M. Oldenburg. A heat map showing the density of collections at sites on the island was generated using QGIS 3.4.

Annotated checklist

The vascular flora of Victoria Island is summarised in an annotated checklist. Classification of lycophytes and ferns follows The Pteridophyte Phylogeny Group (2016). Angiosperms are organized according to the linear classification of flowering plants proposed by The Angiosperm Phylogeny Group (2016). Genera are listed alphabetically within families and species are listed alphabetically within genera. Taxonomy at genus, species and infraspecific levels is based on consideration of the relevant global taxonomic literature, including Elven et al. (2011), treatments in the Flora of North America series (Flora of North America Editorial Committee 1993+), and taxonomic monographs and revisions, such as Mosyakin (2016) and Wiegleb et al. (2017). For each species we provide important synonyms, focusing on names used in critical Canadian (Porsild and Cody 1980, Aiken et al. 2007) or international (Elven et al. 2011) Arctic taxonomic treatments, more recent national or continental treatments, particularly the Flora of North America, and other taxonomic works. Common name(s) in English are mostly from the Flora of North America series and Brouillet et al. (2010+). Global distribution summaries are those described by Elven et al. (2011). For each taxon recorded from Victoria Island we include a summary of the broader distribution in the Canadian Arctic, referencing primary and secondary literature, and, in a few case, unpublished specimens. For species that are rare on Victoria Island and known from only one or few collections, we provide information on habitat, when available. Photographs are included for a subset of taxa to facilitate identification and illustrate habitats. We also provide keys to the families, genera, species and infraspecific taxa, to facilitate identification of plants on the island. Keys were adapted from diverse published sources. Measurements in the keys refer to lengths unless otherwise indicated.

All species reported for the study area are documented by one or more voucher specimens, and only vouchered records are included and mapped. Observations of species noted by Porsild (1955), which were mapped in subsequent work (Porsild 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007), are mentioned in the text unless we cite a voucher obtained by a different collector from the same area, confirming the occurrence of the taxon in that area. These comments thus identify occurrences mapped in earlier treatments for which no voucher exists. For each collection, we list the collector(s), collection number or s.n. [sin nombre = without number] if no collection number exists, and the code(s) identifying the herbaria where the collection is housed. Nineteenth century collections are summarized in Suppl. material 1 and not included in the annotated checklist, except in a few cases. In a few cases, unvouchered observations of rare taxa in the Cambridge Bay are noted, but not mapped; collections should be obtained for proper documentation of these occurrences.

To simplify publication of voucher information, we assigned each collection to a general area of the island. Where possible, we used general areas as described on specimen labels. In cases where no or vague site information is given on labels, however, we assigned specimens to a nearby named place. For example, collections by Edlund reported from south of Burns Lake were gathered in 1982 and 1987 at sites ca. 40–45 km south or south-southwest of the lake, but on the specimen labels the location is described only as “Geological Survey of Canada peat study location” along with the coordinates. In most cases, the toponyms we use are recognized by the Geographical Names Board of Canada. A few sites names, however, are not officially recognized. Examples include “Oldenburg Lake”, “Trunsky Lake” and “30-Mile Creek”, also known locally as “30 Mile River” and “Halovik River”. Locations of all general areas are shown in Fig. 1. The “Cambridge Bay” area includes all collections from the immediate vicinity of the hamlet, along the road to Ovayok Territorial Park (but not including collections made within the park limit), and along and in the vicinity of the road west of the hamlet, including Long Point and the Augustus Hills. Ulukhaktok includes the immediate area of the hamlet. Collections made by S. Ponomarenko recorded from Greiner L. include specimens taken from throughout the Greiner L. watershed, except those that were gathered close to the west side of Albert Edward Bay, which are recorded as being from that general area. The following abbrevations are used in the Annotated Checklist: B., Bay; C., Cape; Cr., Creek; I., Island; Inl., Inlet; Mts., Mountains; P., Peninsula; Pt., Point; R., River; S., Sound; TP, Territorial Park.

Some toponyms on Victoria Island have changed in recent years. Ferguson Lake, a large lake north of Cambridge Bay that flows into Wellington Bay via the Ekalluk River, is officially known as Tahiryuaq, the Inuinnaqtun name. We use the English name for the lake to avoid confusion with two other lakes on Victoria Island also officially named Tahiryuaq. Both of these are in Northwest Territories, one north of Prince Albert Sound (70°56'2"N, 112°15'7"W) where collections were made by Edlund and the other southeast of the head of Minto Inlet (71°27'2"N, 114°45'8"W). The esker formerly known as Ovayuk/Mount Pelly, where many collections have been made, was renamed Uvayuq, effective 21 September 2012. The esker northwest of Mount Pelly and north of Cambridge Bay formerly known as Mount Lady Pelly (69°15'28"N, 104°48'37"W), where collections were made in 1962, was renamed Amaaqtuq, effective 21 September 2012.

For each taxon recorded from Victoria Island we summarize previous reports of the species occurrence on the island by site and indicate sites for which a taxon is newly recorded here. “Previously recorded” at a site means a species occurrence was stated or mapped for a site in one or more earlier published works, which are cited in the text here, regardless of whether or not voucher information was published, and the earlier report is supported by one or more vouchers cited in the text here, unless otherwise indicated. In most cases, the vouchers cited here are the collections on which the earlier records were based. In many cases, new material has been gathered from sites at which a species was previously reported, particularly those areas that are best collected, like Cambridge Bay and Ulukhaktok. Although we do not, in most cases, comment on the accumulation of material of a species at a particular site, we do cite all the relevant material known to us from each site.

“Newly recorded” at a site means the current study is the first to publish an occurrence of a species at a particular site. Such new records reported here include collections made during our fieldwork from 2008 on, earlier collections that previous workers did not consider in their floristic treatments, earlier collections that were not processed and available for study until recently, and new identifications of material known to previous authors, either because previous determinations were incorrect or in light of revised taxon circumscriptions. In all cases we include explicit citation of one or more voucher specimens supporting new records.

Thannheiser et al. (2001) reported species from numerous sites across Victoria Island, including many listed as new records for sites. Because we have not reviewed any voucher specimens supporting those reports, nor are we aware of the existence of vouchers for all reports, we do not include these records in our maps. Nevertheless, we recognize the importance of the work done by Thannheiser and colleagues over many years on Victoria Island and note all instances where Thannheiser et al. (2001) report a species from a site for which we have not seen a voucher. In cases where Thannheiser et al. (2001) newly reported a species from an area and we have confirmed and cite a collection made by a different collector in the same area, we state that occurrence of the species in the area as reported by Thannheiser et al. (2001) is confirmed (“conf.”); this does not mean we have confirmed a voucher taken by Thannheiser and colleagues supporting their report of the species. This is the case, for example, for many records newly reported from Johansen Bay by Thannheiser et al. (2001) confirmed to be present in that area by collections we made in that area in 2008.

Patterns of floristic diversity

To characterize patterns of floristic diversity on Victoria Island we scored, based on our dataset, the presence of species/taxa in the following regions: Nunavut and Northwest Territories, the six areas that we aimed to document comprehensively in 2008 and 2010, two additional well-collected areas (Cambridge Bay, Ulukhaktok), and Ovayok Territorial Park, the only protected area on the island (Table 2). The geographical limits of all these areas correspond to the way the sites are listed in the annotated checklist (see above), except we included Murray Point in the Johansen Bay area rather than treating it separately. We determined the area (km2) represented by each of these general study areas by drawing a bounding box around all sites in Google Earth (Google 2019) and using the polygon measuring tool: Oterkvik Point: 355 km2; Johansen Bay: 212 km2; Sinclair Creek, 1 km2; Boot Inlet: 8.77 km2; the head of Minto Inlet: 128 km2; Kuujjua River: 198 km2; Cambridge Bay: 200 km2; Ulukhaktok: 16.5 km2. We constructed species discovery curves for the six 2008 and 2010 areas to characterize the cumulative number of species recorded at each as a function of the time (days) we spent searching for species diversity. We also scored the presence of taxa in the Circumpolar Vegetation Map bioclimate subzones C and D across Victoria Island (CAVM Team 2003), in the Nunavut portion of the island, and the ecological regions in the Northwest Territories portion of the island defined by Ecosystem Classification Group (2013). For the Nunavut portion of the island we additionally scored presence/absence of taxa east and west of Wellington Bay and in two subzones of bioclimate subzone C, one comprising Storkerson Peninsula, the head and west side of Hadley Bay and Natkusiak Peninsula and the other comprising the rest of the subzone across the middle of the island.

Results

We compiled a dataset of some 7031 unique collections of vascular plants from Victoria Island (Suppl. material 2). Although many sites on the island have been visited by vascular plant collectors, there is considerable range in density of collections at particular sites and areas across the island, with few collections at many sites and many collections from only a few sites (Fig. 4). The most densely collected areas, in terms of numbers of unique collections, are Boot Inlet, Cambridge Bay, Johansen Bay, Kuujjua River, the head of Minto Inlet, Oterkvik Point and Ulukhaktok. Locations of collecting sites of major collectors on Victoria Island are shown in Fig. 5. The greatest number of specimens were collected in the 1940s, 1980s, 2000s, and 2010s, ranging in each of those decades from 1074 to 1850 collections (Fig. 6A). There are no collections in our dataset gathered on the island in the 1920s and 1930s, and few collections included here were gathered in the 1910s (54) and 1970s (49) (Fig. 5). The most rapid accumulation of collections on Victoria Island has occurred since 2000 (Fig. 6B).

Figure 4. 

A Locations of all collecting sites on Victoria Island B heat map showing density of collections at sites on Victoria Island. Lighter colour indicates lesser density of collections and darker colour indicates greater density of collections at a site.

Figure 5. 

Locations of collecting sites of major collectors on Victoria Island. A L.J. Gillespie et al. 2008 B L.J. Gillespie et al. 2010 C M. Oldenburg D A.E. Porsild E S.A. Edlund (existing) F S.A. Edlund (backlog) G B.A. Bennett H S. Ponomarenko.

Figure 6. 

A Number of collections on Victoria Island by decade included in the current study, from 1910 to the present B cumulative number of collections made on Victoria Island by decade, from 1910 to the present.

The vascular flora of Victoria Island comprises 38 families, 108 genera, 272 species, and 17 additional taxa (Table 1). Of the 289 taxa known on the island, 237 are recorded from the Northwest Territories portion of the island and 277 from the Nunavut part. Lycophytes comprise one order, family, genus and species. Monilophytes comprise two orders, four families, four genera and six families. Angiosperms comprise 18 orders, 103 genera, 33 families, 265 species and 17 additional taxa. Monocots comprise three orders, six families, 24 genera, 83 species, and nine infraspecific taxa. Eudicots are represented by fifteen orders, 27 families, 79 genera, 182 species, and eight additional taxa. A complete list of taxa is presented in Table 2 and the Annotated checklist.

Number of genera and species in each family of vascular plants recorded from Victoria Island. The higher level classification of angiosperms follows The Angiosperm Phylogeny Group (2016).

Order Family Genera Species/Taxa
Lycophytes Lycopodiales Lycopodiaceae 1 1
Monilophytes Equisetales Equisetaceae 1 3
Polypodiales Cystopteridaceae 1 1
Dryopteridaceae 1 1
Woodsiaceae 1 1
Monocots Alismatales Potamogetonaceae 1 2
Tofieldiaceae 1 2
Asparagales Orchidaceae 1 1
Poales Juncaceae 2 7/8
Cyperaceae 2 33/35
Poaceae 17 38/44
Eudicots Ranunculales Ranunculaceae 6 13
Papaveraceae 1 4
Superasterids Caryophyllales Plumbaginaceae 1 1
Polygonaceae 2 2
Caryophyllaceae 7 19/21
Amaranthaceae 1 1
Montiaceae 1 1
Superasterids Asterids Ericales Primulaceae 2 3
Ericaceae 8 11
Gentianales Rubiaceae 1 1
Gentianaceae 2 2
Boraginales Boraginaceae 1 2
Lamiales Plantaginaceae 2 2
Lentibulariaceae 1 1
Orobanchaceae 2 8
Asterales Asteraceae 13 25/26
Superrosids Saxifragales Saxifragaceae 3 15
Haloragaceae 1 1
Rosids Fabales Fabaceae 4 10
Rosales Rosaceae 3 13/15
Campanulaceae 1 1
Fagales Betulaceae 1 1
Celastrales Celastraceae 1 1
Malpighiales Salicaceae 1 10/11
Linaceae 1 1
Myrtales Onagraceae 2 2
Brassicales Brassicaceae 10 31/33
Total 21 38 108 272/289

Three families are represented by more than ten genera: Asteraceae (13), Brassicaceae (10), and Poaceae (17). Of the remaining 35 families, 21 are represented by a single genus, eight by two genera, two by three, one by four, one by five, one by seven and one by eight (Table 1). The only hybrid recorded with a hybrid formula on the island is within the genus Salix. Two infraspecific taxa are recorded on the island in 13 species: Artemisia borealis (Asteraceae), Braya glabella, B. thorild-wulffii (Brassicaceae), Silene involucrata, S. uralensis (Caryophyllaceae), Carex bigelowii, Eriophorum scheuchzeri (Cyperaceae), Juncus arcticus (Juncaceae), Anthoxanthum monticola, Elymus alaskanus, Festuca rubra, Poa arctica (Poaceae), Potentilla arenosa (Rosaceae). Three infraspecific taxa of Poa pratensis are recorded on Victoria Island.

The number of collections per taxon from Victoria Island ranges from 1 to 162 (mean 24 ± 23). Thirty-nine taxa are known on the island from a single collection: Eurybia sibirica, Senecio lugens (Asteraceae), Mertensia drummondii (Boraginaceae), Braya thorild-wulffii subsp. glabrata, Cardamine bellidifolia, Crucihimalaya bursifolia, Draba norvegica, D. pauciflora, Erysimum coarctatum, Parrya nudicaulis (Brassicaceae), Sabulina elegans, S. stricta, Sagina caespitosa (Caryophyllaceae), Eriophorum russeolum subsp. albidum (Cyperaceae), Andromeda polifolia (Ericaceae), Oxytropis deflexa var. foliolosa (Fabaceae), Luzula wahlenbergii (Juncaceae), Montia fontana (Montiaceae), Corallorhiza trifida (Orchidaceae), Castilleja pallida var. caudata, Pedicularis hirsuta (Orobanchaceae), Anthoxanthum nitens subsp. nitens, Bromus pumpellianus, Deschampsia cespitosa subsp. cespitosa, D. sukatschewii, Festuca rubra subsp. rubra, Lolium perenne, Poa pratensis subsp. pratensis (Poaceae), Stuckenia filiformis, S. vaginata (Potamogetonaceae), Pulsatilla nuttalliana (Ranunculaceae), Potentilla hyparctica subsp. hyparctica, P. × prostrata, P. vulcanicola, Rubus chamaemorus L. (Rosaceae), Galium aparine (Rubiaceae), Salix arctophila, S. ovalifolia var. ovalifolia, S. planifolia (Salicaceae). Seven taxa are known from two collections: Braya thorild-wulffii subsp. thorild-wulffii, Draba fladnizensis, D. oligosperma (Brassicaceae), Arenaria longipedunculata (Caryophyllaceae), Equisetum scirpoides (Equisetaceae), Anthoxanthum monticola subsp. monticola (Poaceae) and Ranunculus sulphureus (Ranunculaceae). Three taxa are known from three collections: Antennaria monocephala subsp. angustata, Artemisia tilesii (Asteraceae) and Carex bicolor (Cyperaceae). Of the remaining taxa, 26 are known from 4–5 collections, 31 from 6–10, 51 from 11–19, 41 from 21–30, 28 from 31–40, 27 from 41–50 and 16 from 51–59. Fifteen species are known from 61–91 collections: Parrya arctica (Brassicaceae), Sabulina rubella, Silene uralensis subsp. uralensis (Caryophyllaceae), Carex aquatilis subsp. stans, C. fuliginosa subsp. misandra, C. membranacea, C. scirpoidea subsp. scirpoidea (Cyperaceae), Pedicularis lanata (Orobanchaceae), Arctagrostis latifolia subsp. latifolia, Dupontia fisheri, Festuca baffinensis, Poa glauca subsp. glauca (Poaceae), Bistorta vivipara (Polygonaceae), Dryas integrifolia subsp. integrifolia (Rosaceae) and Salix richardsonii (Salicaceae). Three species are known from over 100 collections: Draba corymbosa (102), Salix arctica (162), Draba cinerea (114) and Stellaria longipes (113).

Twenty-one taxa in eight families are newly recorded for the flora of Victoria Island, namely Artemisia tilesii, Senecio lugens, Taraxacum scopulorum (Asteraceae), Crucihimalaya bursifolia, Draba fladnizensis, D. juvenilis, D. pilosa, D. simmonsii (Brassicaceae), Carex bigelowii subsp. bigelowii, Eriophorum russeolum subsp. albidum (Cyperaceae), Anthoxanthum monticola subsp. monticola, Bromus pumpellianus, Deschampsia cespitosa subsp. cespitosa, D. sukatschewii, Festuca rubra subsp. rubra, Lolium perenne, Poa pratensis subsp. pratensis (Poaceae), Stuckenia filiformis (Potamogetonaceae), Potentilla × prostrata (Rosaceae), Galium aparine (Rubiaceae) and Salix ovalifolia var. ovalifolia (Salicaceae). Eight of these are new to the flora of the Canadian Arctic Archipelago: Senecio lugens, Draba juvenilis, D. pilosa, Anthoxanthum monticola subsp. monticola, Bromus pumpellianus, Deschampsia cespitosa subsp. cespitosa, Poa pratensis subsp. pratensis, Salix ovalifolia var. ovalifolia. One of these, Galium aparine, is newly recorded for the flora of Nunavut. Four of these first records for Victoria Island are introduced plants discovered in Cambridge Bay in 2017: three grasses (Festuca rubra subsp. rubra, Lolium perenne, and Poa pratensis subsp. pratensis) and Galium aparine. One taxon, Juncus arcticus subsp. arcticus, is newly recorded from the Northwest Territories.

Considering diversity in the CAVM subzones present on the island, 157 taxa are recorded in subzone C, 283 in subzone D, and 149 taxa are recorded in both subzones (Suppl. material 3). Five taxa recorded in both subzones are known from single occurrences in subzone C (Carex vaginata, Cystopteris fragilis, Equisetum arvense subsp. alpestre, Huperzia arctica, Woodsia glabella). Eight taxa are recorded in subzone C that are not recorded in subzone D: Braya thorild-wulffii subsp. glabrata, Cardamine bellidifolia, Draba pauciflora, Deschampsia cespitosa subsp. cespitosa (borderline subzone C/D), Puccinellia bruggemannii, Ranunculus sabinei, Ranunculus sulphureus and Saxifraga flagellaris subsp. platysepala. A total of 134 taxa are recorded in subzone D that are not recorded in subzone C.

Within the Northwest Territories, 125 taxa are recorded in the West Prince Albert Lowland Mid Arctic (MA) ecoregion, 37 in the West Prince Albert Upland MA ecoregion, six in the East Prince Albert Plain MA ecoregion, 51 in the Shaler Mountains MA ecoregion, 76 in the Tahiryuak Upland MA ecoregion, 29 in Wollaston Peninsula MA ecoregion and 231 in Prince Albert Coastlands Low Arctic-north ecoregion (Suppl. material 3).

Of the eight general areas on Victoria Island that have been botanically explored the most, the greatest diversity of vascular plants is recorded in Ulukhaktok, where 194 taxa are known (Table 2). The next most-diverse sites, in descending order of diversity, are Cambridge Bay (183 taxa), Johansen Bay (181), Kuujjua R. (176), the head of Minto Inlet (173), Boot Inlet (139), Oterkvik Point (127), Sinclair Cr. (85) and Ovayok Territorial Park (57). If the flora of Ovayok is considered as part of the Cambridge Bay area, 187 taxa are recorded in the area; only four species are recorded from Ovayok that are not otherwise known from the Cambridge Bay area (Cystopteris fragilis, Poa abbreviata subsp. abbreviata, Potentilla uschakovii, Tofieldia pusilla), whereas there are many species recorded from Cambridge Bay not known to occur in the park.

Species discovery curves for each of the six areas we aimed to document comprehensively in 2008 and 2010 each indicate a generally consistent increase in number of new species found with each additional day of exploration (Fig. 7). Curves for all six sites either reach or approach a plateau, indicating a slowing down in the number of new species documented on the last day(s) we spent in each area.

Figure 7. 

Species discovery curves for six sites that were intensively surveyed by Gillespie et al. for vascular plant biodiversity in 2008 (Johansen Bay, Oterkvik Point, Sinclair Creek) and 2010 (Boot Inlet, Kuujjua River, the head of Minto Inlet).

Vascular plants recorded from Victoria Island. The table records whether or not each taxon is recorded in Northwest Territories and Nunavut, eight sites on the island that have been explored comprehensively (NWT: Ulukhaktok, Boot Inlet, Kuujjua River, the head of Minto Inlet; NU: Oterkvik Point, Johansen Bay, Sinclair Creek, Cambridge Bay) as well as Ovayok Territorial Park, Nunavut, the only protected area on Victoria Island. Occurrences at other sites are recorded in the annotated checklist and on the distribution maps. Taxa are listed by major clade, and then alphabetically by family.

Family Taxon Ulukhaktok Boot Inlet Kuujjua River Head of Minto Inlet Northwest Territories Oterkvik Point Johansen Bay Sinclair Creek Cambridge Bay Ovayok Territorial Park Nunavut
Lycophytes
Lycopodiaceae Huperzia arctica Sipliv.
Monilophytes
Cystopteridaceae Cystopteris fragilis (L.) Bernh.
Dryopteridaceae Dryopteris fragrans (L.) Schott
Equisetaceae Equisetum arvense subsp. alpestre (Wahlenb.) Schönsw. & Elven
Equisetum scirpoides Michx.
Equisetum variegatum Schleich. ex F.Weber & D.Mohr subsp. variegatum
Woodsiaceae Woodsia glabella R.Br.
Monocots
Cyperaceae Carex aquatilis subsp. stans (Drejer) Hultén
Carex atrofusca Schkuhr
Carex bicolor All.
Carex bigelowii subsp. lugens (Holm) T.V.Egorova
Carex bigelowii Torr. ex Schwein. subsp. bigelowii
Carex borealipolaris S.R.Zhang
Carex capillaris subsp. fuscidula (V.I.Krecz. ex T.V.Egorova) Á.Löve & D.Löve
Carex chordorrhiza L.f.
Carex fuliginosa subsp. misandra (R.Br.) Nyman
Carex glacialis Mack.
Carex glareosa Wahlenb. subsp. glareosa
Carex krausei Boeckeler
Carex marina Dewey
Carex maritima Gunnerus
Cyperaceae Carex membranacea Hook.
Carex microglochin Wahlenb.
Carex myosuroides Vill.
Carex nardina Fr.
Carex petricosa Dewey subsp. petricosa
Carex rariflora (Wahlenb.) Sm.
Carex rupestris All.
Carex saxatilis L.
Carex scirpoidea Michx. subsp. scirpoidea
Carex simpliciuscula subsp. subholarctica (T.V.Egorova) Saarela
Carex subspathacea Wormsk.
Carex ursina Dewey
Carex vaginata Tausch
Eriophorum angustifolium Honck.
Eriophorum brachyantherum Trautv. & C.A.Mey.
Eriophorum callitrix C.A.Mey.
Eriophorum russeolum subsp. albidum (F.Nyl.) Väre
Eriophorum scheuchzeri Hoppe subsp. scheuchzeri
Eriophorum scheuchzeri subsp. arcticum M.S.Novos.
Eriophorum triste (Th.Fr.) Hadač & Á.Löve
Eriophorum vaginatum L. subsp. vaginatum
Juncaceae Juncus arcticus subsp. alaskanus Hultén
Juncus arcticus Willd. subsp. arcticus
Juncus biglumis L.
Juncus leucochlamys V.J.Zinger ex V.I.Krecz.
Juncus triglumis subsp. albescens (Lange) Hultén
Luzula confusa Lindeb.
Juncaceae Luzula nivalis (Laest.) Spreng.
Luzula wahlenbergii Rupr.
Poaceae Alopecurus borealis Trin.
Anthoxanthum arcticum Veldkamp
Anthoxanthum monticola (Bigelow) Veldkamp subsp. monticola
Anthoxanthum monticola subsp. alpinum (Sw. ex Willd.) Soreng
Anthoxanthum nitens (Weber) Y.Schouten & Veldkamp subsp. nitens
Arctagrostis latifolia (R.Br.) Griseb. subsp. latifolia
Arctophila fulva (Trin.) Andersson
Bromus pumpellianus Scribn.
Calamagrostis purpurascens R.Br.
Calamagrostis stricta subsp. groenlandica (Schrank) Á.Löve
Deschampsia brevifolia R.Br.
Deschampsia cespitosa (L.) P.Beauv. subsp. cespitosa
Deschampsia sukatschewii (Popl.) Roshev.
Dupontia fisheri R.Br.
Elymus alaskanus (Scribn. & Merr.) Á.Löve subsp. alaskanus
Elymus alaskanus subsp. hyperarcticus (Polunin) Á.Löve & D.Löve
Festuca baffinensis Polunin
Festuca brachyphylla Schult. & Schult.f. subsp. brachyphylla
Festuca hyperborea Holmen ex Fred.
Festuca rubra subsp. arctica (Hack.) Govor.
Festuca rubra L. subsp. rubra
Poaceae Leymus mollis subsp. villosissimus (Scribn.) Á.Löve & D.Löve
Lolium perenne L.
Phippsia algida (Sol.) R.Br.
Pleuropogon sabinei R.Br.
Poa abbreviata R.Br. subsp. abbreviata
Poa arctica R.Br. subsp. arctica
Poa arctica subsp. caespitans Simmons ex Nannf.
Poa glauca Vahl subsp. glauca
Poa hartzii Gand. subsp. hartzii
Poa pratensis L. subsp. pratensis
Poa pratensis subsp. alpigena (Lindm.) Hiitonen
Poa pratensis subsp. colpodea (Th.Fr.) Tzvelev
Puccinellia andersonii Swallen
Puccinellia angustata E.L.Rand & Redfield
Puccinellia arctica (Hook.) Fernald & Weath.
Puccinellia banksiensis Consaul
Puccinellia bruggemannii T.J.Sørensen
Puccinellia nuttalliana (Schult.) Hitchc.
Puccinellia phryganodes subsp. neoarctica (Á.Löve & D.Löve) Elven
Puccinellia tenella subsp. langeana (Berlin) Tzvelev
Puccinellia vaginata (Lange) Fernald & Weath.
Puccinellia vahliana (Liebm.) Scribn. & Merr.
Trisetum spicatum (L.) K.Richt.
Potamogetonaceae Stuckenia vaginata (Turcz.) Holub
Potamogetonaceae Stuckenia filiformis (Pers.) Börner
Tofieldiaceae Tofieldia coccinea Richardson
Tofieldia pusilla (Michx.) Pers.
Eudicots
Amaranthaceae Suaeda calceoliformis (Hook.) Moq.
Asteraceae Antennaria friesiana (Trautv.) Ekman subsp. friesiana
Antennaria media subsp. compacta (Malte) Chmiel.
Antennaria monocephala subsp. angustata (Greene) Hultén
Arnica angustifolia Vahl subsp. angustifolia
Artemisia borealis Pall. subsp. borealis
Artemisia borealis subsp. richardsoniana (Besser) Korobkov
Artemisia hyperborea Rydb.
Artemisia tilesii Ledeb.
Askellia pygmaea (Ledeb.) Sennikov
Erigeron compositus Pursh
Erigeron eriocephalus J.Vahl
Erigeron humilis Graham
Erigeron porsildii G.L.Nesom & D.F.Murray
Eurybia sibirica (L.) G.L.Nesom
Hulteniella integrifolia (Richardson) Tzvelev
Petasites frigidus (L.) Fr. subsp. frigidus
Senecio lugens Richardson
Symphyotrichum pygmaeum (Lindl.) Brouillet & Selliah
Taraxacum ceratophorum (Ledeb.) DC.
Taraxacum holmenianum Sahlin
Asteraceae Taraxacum hyparcticum Dahlst.
Taraxacum phymatocarpum J.Vahl
Taraxacum scopulorum (A.Gray) Rydb.
Tephroseris frigida (Richardson) Holub
Tephroseris palustris subsp. congesta (R.Br.) Holub
Tripleurospermum maritimum subsp. phaeocephalum (Rupr.) Hämet-Ahti
Betulaceae Betula glandulosa Michx.
Boraginaceae Mertensia drummondii (Lehm.) G.Don
Mertensia maritima subsp. tenella (Th.Fr.) Elven & Skarpaas
Brassicaceae Braya glabella Richardson subsp. glabella
Braya glabella subsp. purpurascens (R.Br.) Cody
Braya humilis (C.A.Mey.) B.L.Rob. subsp. humilis
Braya thorild-wulffii Ostenf. subsp. thorild-wulffii
Braya thorild-wulffii subsp. glabrata J.G. Harris
Cardamine bellidifolia L.
Cardamine digitata Richardson
Cardamine polemonioides Rouy
Cochlearia groenlandica L.
Crucihimalaya bursifolia (DC.) D.A.German & A.L.Ebel
Descurainia sophioides (Fisch. ex Hook.) O.E.Schulz
Draba arctica J.Vahl
Draba cinerea Adams
Draba corymbosa R.Br. ex DC.
Draba fladnizensis Wulfen
Draba glabella Pursh
Draba juvenilis Kom.
Brassicaceae Draba lactea Adams
Draba micropetala Hook.
Draba nivalis Lilj.
Draba norvegica Gunn.
Draba oblongata R.Br. ex DC.
Draba oligosperma Hook.
Draba pauciflora R.Br.
Draba pilosa Adams ex DC.
Draba simmonsii Elven & Al-Shehbaz
Draba subcapitata Simmons
Erysimum coarctatum Fernald
Erysimum pallasii (Pursh) Fernald
Eutrema edwardsii R.Br.
Parrya arctica R.Br.
Parrya nudicaulis (L.) Regel
Physaria arctica (Wormsk. ex Hornem.) O’Kane & Al-Shehbaz
Campanulaceae Campanula uniflora L.
Caryophyllaceae Arenaria humifusa Wahlenb.
Arenaria longipedunculata Hultén
Cerastium arcticum Lange
Cerastium beeringianum Cham. & Schltdl.
Cerastium regelii Ostenf.
Honckenya peploides subsp. diffusa (Hornem.) Hultén
Sabulina elegans (Cham. & Schltdl.) Dillenb. & Kadereit
Sabulina rossii (R.Br. ex Richardson) Dillenb. & Kadereit
Sabulina rubella (Wahlenb.) Dillenb. & Kadereit
Sabulina stricta (Sw.) Rchb.
Sagina caespitosa Lange
Sagina nivalis Fr.
Caryophyllaceae Silene acaulis (L.) Jacq.
Silene involucrata (Cham. & Schltdl.) Bocquet subsp. involucrata
Silene involucrata subsp. tenella (Tolm.) Bocquet
Silene ostenfeldii (A.E.Porsild) J.K.Morton
Silene uralensis (Rupr.) Bocquet subsp. uralensis
Silene uralensis subsp. arctica (Th.Fr.) Bocquet
Stellaria crassifolia Ehrh.
Stellaria humifusa Rottb.
Stellaria longipes Goldie
Celastraceae Parnassia kotzebuei Cham. ex Spreng.
Ericaceae Andromeda polifolia L.
Arctous alpina (L.) Nied.
Arctous rubra (Rehder & E.H.Wilson) Nakai
Cassiope tetragona (L.) D.Don subsp. tetragona
Empetrum nigrum L.
Rhododendron lapponicum (L.) Wahlenb.
Orthilia secunda subsp. obtusata (Turcz.) Böcher
Pyrola grandiflora Radius subsp. grandiflora
Vaccinium vitis-idaea subsp. minus (Lodd., G. Lodd. & W. Lodd.) Hultén
Fabaceae Astragalus alpinus L.
Astragalus richardsonii E.Sheld.
Hedysarum americanum (Michx.) Britton
Hedysarum boreale subsp. mackenziei (Richardson) S.L.Welsh
Lupinus arcticus S.Watson subsp. arcticus
Oxytropis arctica R.Br. var. arctica
Oxytropis arctobia Bunge
Oxytropis deflexa var. foliolosa (Hook.) Barneby
Fabaceae Oxytropis maydelliana Trautv.
Oxytropis varians (Rydb.) K.Schum.
Gentianaceae Gentianella propinqua (Richardson) J.M.Gillett subsp. propinqua
Lomatogonium rotatum (L.) Fr. subsp. rotatum
Haloragaceae Myriophyllum sibiricum Kom.
Lentibulariaceae Pinguicula vulgaris L.
Linaceae Linum lewisii Pursh subsp. lewisii
Montiaceae Montia fontana L.
Onagraceae Chamaenerion latifolium (L.) Sweet
Epilobium arcticum Sam.
Orchidaceae Corallorhiza trifida Châtel.
Orobanchaceae Castilleja elegans Malte
Castilleja pallida var. caudata (Pennell) B.Boivin
Pedicularis albolabiata (Hultén) Kozhevn
Pedicularis arctoeuropaea (Hultén) Molau & D.F.Murray
Pedicularis capitata Adams
Pedicularis hirsuta L.
Pedicularis lanata Willd. ex Cham. & Schltdl.
Pedicularis langsdorffii subsp. arctica (R.Br.) Pennell ex Hultén
Papaveraceae Papaver cornwallisense D.Löve
Papaver dahlianum Nordh.
Papaver hultenii Knaben
Papaver lapponicum (Tolm.) Nordh.
Plantaginaceae Hippuris lanceolata Retz.
Plantago canescens Adams
Plumbaginaceae Armeria scabra Pall. ex Roem. & Schult.
Polygonaceae Bistorta vivipara (L.) Delarbre
Oxyria digyna (L.) Hill
Primulaceae Androsace chamaejasme subsp. andersonii (Hultén) Hultén
Androsace septentrionalis L.
Primula stricta Hornem.
Ranunculaceae Anemone parviflora Michx.
Caltha palustris subsp. radicans (T.F.Forst.) Hook.
Halerpestes cymbalaria (Pursh) Greene
Pulsatilla nuttalliana (DC.) Spreng.
Ranunculus arcticus Richardson
Ranunculus codyanus B.Boivin
Ranunculus gmelinii DC. subsp. gmelinii
Ranunculus hyperboreus Rottb. subsp. hyperboreus
Ranunculus nivalis L.
Ranunculus pygmaeus Wahlenb.
Ranunculus sabinei R.Br.
Ranunculus sulphureus Sol.
Rosaceae Dryas integrifolia Vahl subsp. integrifolia
Potentilla anserina subsp. groenlandica Tratt.
Potentilla arenosa (Turcz.) Juz. subsp. arenosa
Potentilla arenosa subsp. chamissonis (Hultén) Elven & D.F.Murray
Potentilla hyparctica Malte subsp. hyparctica
Potentilla nivea L.
Potentilla pedersenii (Rydb.) Rydb.
Potentilla × prostrata Rottb.
Potentilla pulchella R.Br.
Potentilla subgorodkovii Jurtzev
Potentilla subvahliana Jurtzev
Potentilla tikhomirovii Jurtzev
Potentilla uschakovii Jurtzev
Rosaceae Potentilla vulcanicola Juz.
Rubus chamaemorus L.
Rubiaceae Galium aparine L.
Salicaceae Salix alaxensis (Andersson ex DC.) Coville var. alaxensis
Salix arctica × Salix polaris
Salix arctica Pall.
Salix arctophila Cockerell ex A.Heller
Salix glauca var. stipulata Flod.
Salix niphoclada Rydb.
Salix ovalifolia Trautv. var. ovalifolia
Salix planifolia Pursh
Salix polaris Wahlenb.
Salix reticulata L.
Salix richardsonii Hook.
Saxifragaceae Chrysosplenium rosendahlii Packer
Chrysosplenium tetrandrum Th.Fr.
Micranthes foliolosa (R.Br.) Gornall
Micranthes hieraciifolia (Waldst. & Kit. ex Willd.) Haw.
Micranthes nivalis (L.) Small
Micranthes tenuis (Wahlenb.) Small
Saxifraga rivularis subsp. arctolitoralis (Jurtzev & V.V.Petrovsky) M.H.Jørg. & Elven
Saxifraga aizoides L.
Saxifraga cernua L.
Saxifraga cespitosa L.
Saxifraga flagellaris subsp. platysepala (Trautv.) A.E.Porsild
Saxifraga hirculus L.
Saxifraga hyperborea R.Br.
Saxifraga oppositifolia L.
Saxifraga rivularis L.
Saxifraga tricuspidata Rottb.
Total 194 139 176 173 237 127 181 85 183 57 277

Discussion

We recorded 272 species and 289 taxa on Victoria Island, including 21 taxa newly reported for the island. This represents an increase of 4.3% from the 277 taxa previously recorded from Victoria Island (Aiken et al. 2007, Gillespie et al. 2015, Saarela et al. 2017b), which includes several first records we previously reported from the island based on 2008 and 2010 collections. Eight taxa are newly recorded for the Canadian Arctic Archipelago, bringing the number of taxa known for the region to 383, a 2.1% increase relative to the 375 taxa previously known from the region (Gillespie et al. 2015). This increase in vascular plant diversity documented in the study area, based on new fieldwork and study and re-evaluation of herbarium material, is consistent with the results of our other floristic studies of Arctic areas, which followed the same approach (Saarela et al. 2013, Gillespie et al. 2015, Saarela et al. 2017b). It is likely there are few areas of the Canadian Arctic where focused botanical exploration would be unlikely to result in an increase in the number of documented species in a local flora.

The greatest regional vascular plant diversity on Victoria Island is recorded from Ulukhaktok (188 species, seven infraspecific taxa, one hybrid) and the next-greatest diversity is recorded from Cambridge Bay (176 species, 11 infraspecific taxa, one hybrid), with about 3.5% fewer taxa recorded than Ulukhaktok. This was an unexpected result, as we had predicted the Cambridge Bay area to be richer because (1) there has been more exploration and collecting there (1422 unique collections in our dataset) compared to Ulukhaktok (915 unique collections), and (2) the Cambridge Bay area, as we have defined it, including the area east of the community along the road to Ovayok Territorial Park and west of the community to the Augustus Hills area, is considerably larger (200 km2) than the Ulukhaktok area (16.5 km2) where collections have been made. In addition to different levels of species richness, the floras of the two areas are dissimilar. Although a total of 150 taxa are documented in both areas, 43 are recorded from Uluhaktok that are not known from Cambridge Bay and 33 from Cambridge Bay that are not known from Ulukhaktok; 61 taxa recorded on the island are not recorded from either area (Table 2). Some of the differences are likely attributable to variation in geology in the areas, with both acidic and calcareous rocks in the immediate Ulukhaktok area and primarily calcareous ones in the Cambridge Bay area. Species with a preference for granitic substrates recorded in Ulukhaktok include Anthoxanthum nitens subsp. nitens, Arctous alpina, Carex nardina, Dryopteris fragrans, Huperzia arctica and Rhododendron lapponicum; none of these is known from Cambridge Bay, though all but Anthoxanthum nitens are recorded elsewhere on southeastern Victoria Island in areas where granitic outcrops are known, such as the Ferguson Lake area north of Cambridge Bay. The flora of Ulukhaktok also contains a strong component of species with western or Beringian distributions that do not extend to southeastern Victoria Island or are not yet recorded from southeastern Victoria Island if they do extend that far eastwards on the island. Examples of such taxa are Salix niphoclada, Artemisia borealis subsp. richardsoniana, Erigeron compositus, E. porsildii, Hedysarum americanum, Gentianella propinqua and Lomatogonium rotatum. The flora of Cambridge Bay, reciprocally, includes taxa with eastern or amphi-Atlantic distributions not known from as far west as Ulukhaktok, such as Carex bigelowii subsp. bigelowii, as well as taxa that are at their northern limits along southern Victoria Island, such as Carex chordorrhiza, Castilleja pallida var. caudata, Myriophyllum sibiricum and Salix glauca var. stipulata. The 57 taxa recorded from Ovayok Territorial Park is an underrepresentation of true diversity within the park because no collectors have yet attempted to complete a comprehensive survey of the park flora, and at least a few taxa have been observed in the park that are not yet documented by vouchers, as noted in the annotated checklist.

The distribution maps presented here serve as updates to those produced over the decades (Porsild 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Compared to these, our study is novel in that every mapped occurrence is supported by a voucher specimen (this is not the case in Porsild (1957) and Porsild and Cody (1980), for example) and we cite all voucher specimens. In most cases we were able to confirm occurrences of species on Victoria Island mapped in one or more of the earlier works by matching them with specimens. The maps also include all of our recent collections as well as numerous historical collections that were not considered in earlier treatments. Our study includes the first detailed distribution mapping on Victoria Island for some Arctic taxa whose circumscriptions have been revised in light of recent taxonomic study, including Papaver and Potentilla. In both of these genera, distribution maps covering the entire Canadian Arctic Archipelago and/or the Arctic mainland are not yet available. Distribution maps following recent taxonomy are available, however, for northern Quebec and Labrador for many taxa (Payette 2013, 2015, 2018).

There are few introduced vascular plant species in the Canadian Arctic Archipelago, and none that are considered to be invasive (Aiken et al. 2007). Accordingly, the vascular flora of Victoria Island comprises 98.6% native taxa. Only four taxa recorded on Victoria Island are non-native: three grasses, Festuca rubra subsp. rubra, Lolium perenne, Poa pratensis subsp. pratensis, and a bedstraw (Galium aparine). All of these were collected in 2017, in Cambridge Bay, growing in the same spot, where they were likely planted as part of a seed mixture. Galium aparine likely grew from seed contaminating the grass seed mixture; the taxon is likely extirpated, as we collected the single plant seen at the site. We do not know if any of these taxa persist at the site. Although there is currently no evidence for the occurrence of widespread invasion of non-native vascular plants on Victoria Island, Cambridge Bay and Ulukhaktok, in particular, should be regularly monitored for possible introductions and persistence of such taxa.

The numerous first records of taxa for Victoria Island reported by Gillespie et al. (2015) and here are variously based on collections made as part of our recent fieldwork, re-evaluation of existing herbarium material, and processing and study of historical collections that had not previously been available for scientific study. First records of taxa reported here based on our fieldwork include those collected by Bennett (Anthoxanthum monticola subsp. monticola, Artemisia tilesii, Crucihimalaya bursifolia), Gillespie et al. (Deschampsia sukatschewii, Draba juvenilis, D. pilosa, D. simmonsii, Potentilla × prostrata), Ponomarenko (Eriophorum russeolum subsp. albidum, Stuckenia filiformis) and Saarela (Festuca rubra subsp. rubra, Galium aparine, Lolium perenne, Poa pratensis subsp. pratensis). A subset of first records of species for Victoria Island reported here are based on a combination of recently collected material plus material newly processed from herbarium backlog that was collected years ago (Carex bigelowii subsp. bigelowii, Taraxacum scopulorum) or re-identified (Draba fladnizensis). Newly processed specimens from herbarium backlog also resulted in new first records for the island (Deschampsia cespitosa subsp. cespitosa, Potentilla hyparctica subsp. hyparctica), as did study of existing herbarium material, including some that was apparently overlooked in previous work (Bromus pumpellianus [previously misidentified], Salix ovalifolia var. ovalifolia [previously misidentified], Senecio lugens). These results underscore the importance of field exploration in combination with careful herbarium research, which is generally more time consuming than the field work component of floristic research, when attempting to characterize the flora of an area.

In addition to first records for Victoria Island, the current study documents many new sites for species previously recorded from one or more sites on the island. The majority of these are collections that close major or minor gaps in species’ known distributions. For example, our 2008 fieldwork across southern Victoria Island–in areas where no or few collections had previously been made–resulted, as expected, in collections that close numerous gaps in distribution for taxa otherwise documented elsewhere on the island, across the Canadian Arctic Archipelago and on the adjacent mainland. Our fieldwork on southeastern Victoria Island resulted in collections from many sites that had not previously been explored or documented (e.g., the Greiner Lake watershed, “Trunsky Lake”, “30-Mile Creek”). Some new site records reported here variously represent extensions to the known ranges of species, to the north (Gentianella propinqua, Tofieldia pusilla), south (Festuca hyperborea) and west (Juncus arcticus subsp. arcticus). In a few cases, we report additional collections for species newly reported for the island in Gillespie et al. (2015), based on additional recent collections (e.g., Carex bicolor) or previously unreported collections gathered decades ago but only now liberated from herbarium backlog (e.g., Arenaria humifusa, Eriophorum brachyantherum). Study of existing herbarium material resulted in “discovery” of many collections that were apparently not considered in previous Canadian Arctic floristic efforts, including collections made by A. Dutilly at Boot Inlet, R. Hainault at Mt. Lady Pelly and a subset of the collections made by J.D.H. Lambert at Long Lake. Review and processing of relevant material from the CAN backlog resulted in records from sites from which no or few collections have otherwise been made, including collections by M. Oldenburg from “Oldenburg Lake”, inland sites on the Prince Albert Peninsula, and Read Island. Similarly, the Edlund backlog material from Victoria Island reported here comprises collections from sites from which other collections were already processed at CAN and sites that were not previously represented in herbarium material, like some inland sites on the Storkerson Peninsula. The material collected at Cambridge Bay by Oldenburg in 1944 and Polunin in 1947, which was processed from the CAN backlog as part of this study and is newly published here, did not reveal any new records for the area. However, these collections, being 70+ years old, provide an important temporal element to understanding the flora of the Cambridge Bay region, as Oldenburg and Polunin were the first botanists (amateur and professional, respectively) to make extensive collections there. Polunin’s Cambridge Bay collection records a number of species not present among Oldenburg’s collection from the same area three years earlier, such as Carex atrofusca, C. bigelowii subsp. bigelowii, Carex capillaris subsp. fuscidula, Carex myosuroides, Equisetum variegatum subsp. variegatum and Juncus biglumis.

Thirty-nine taxa are known on the island from a single collection, seven from two collections and three from three collections. All 47 of these taxa may be considered rare on the island, and efforts should be made to discover additional populations. Many of the taxa known from a single collection have not been seen in decades, being known only from collections made in 1915 (Eurybia sibirica, Mertensia drummondii), 1945 (Pedicularis hirsuta), 1946 (Potentilla hyparctica subsp. hyparctica), 1949 (Anthoxanthum nitens subsp. nitens, Montia fontana), 1952 (Potentilla vulcanicola), 1959 (Braya thorild-wulffii subsp. glabrata, Draba norvegica), 1962 (Salix ovalifolia var. ovalifolia), 1964 (Bromus pumpellianus, Erysimum coarctatum, Pulsatilla nuttalliana, Rubus chamaemorus, Salix planifolia, Senecio lugens), 1986 (Cardamine bellidifolia) and 1987 (Draba pauciflora, Sagina caespitosa). The exact original collecting sites for all the collections made prior to the 1980s would likely be impossible to re-locate, since locality information on specimen labels is brief and imprecise. For example, the 1964 collections are part of a larger set of 48 specimens gathered by J.D.H. Lambert from “Long Lake” (Kellogok), a linear lake some 10 km in length with its northwestern end included in (or surrounded by) the southeastern portion of Ovayok Territorial Park. Additional information provided on the labels is brief, including plot numbers 21–27, the coordinates 69°07'N, 104°34'W, and the habitat “sedge meadow” on a subset of collections. The coordinates mark a spot about 750 m west of the mid-point of the lake. We do not know how accurate these coordinates are, nor if they were determined by the collector or secondarily by another worker based on the named locality. The recorded plot numbers suggest the collections were made as part of an ecological study, but we have not been able to align them with published or unpublished research. Other species recorded by Lambert from “Long Lake” include the rare species Lupinus arcticus subsp. arcticus (three collections) and the heaths Empetrum nigrum, Rhododendron tomentosum subsp. decumbens, Vaccinium uliginosum and V. vitis-idaea subsp. minus, most of which are uncommon on the island. The presence of the heaths indicates acidic substrate in the “Long Lake” area, which on southeastern Victoria Island is otherwise known only from the Wellington Bay area. Efforts should be undertaken to explore the “Long Lake” area to try and re-locate the occurrence(s) of these rare taxa, most of which should be relatively conspicuous, particularly if/when in flower, and which have not been seen in the area in over 50 years.

Species discovery at 2008 and 2010 study areas

The species discovery curves for the six sites on Victoria Island at which we aimed to document all vascular plant diversity present indicate, not surprisingly, that species discovery is directly correlated with search intensity: as more days were spent at a site, more species were found. Search intensity is also a function of the number of searchers active in an area and their field botany skills, taxonomic expertise and knowledge of and experience with the flora under study. Some Arctic species are difficult to identify, especially in the field (high-powered magnification is often needed to observe diagnostic characters), such as those in the genera Draba and Potentilla and in groups that field botanists – in the Arctic and elsewhere – tend to be less familiar with, like the grasses (Poaceae) and sedges (Cyperaceae). Specialist knowledge is usually needed to locate and recognize diversity in such challenging groups in the field. Our own experience on Victoria Island serves as an example of this: the Canadian Arctic flora was brand new to one of us (J.M. Saarela) on our 2008 expedition. Reflecting on experience gained with the Canadian Arctic vascular plant flora in both the field and herbarium over the subsequent ten-year period, it is likely that some species present at sites studied in the plant families focused on by that individual (grasses, sedges, rushes) during that expedition were overlooked (J.M. Saarela, pers. obs.). Reciprocally, Puccinellia expert Laurie Consaul, who was also part of the 2008 expedition, focused on documenting diversity in that challenging genus on Victoria Island. Results, based on targeted search efforts, included her locating new populations of P. banksiensis, a species described as new to science that same year that was not then known from the island (Consaul et al. 2008a). This demonstrates how deep experience in a particular taxon, in the field and herbarium, can result in novel discoveries that would likely have otherwise been overlooked by workers less familiar with the group. We suggest the following general rule of thumb for collecting plants in the Canadian Arctic, especially when working in areas that are logistically difficult to access and unlikely to be re-visited by botanists: when one is unsure of the identity of a taxon in the field, and especially if one is unsure of whether or not they have already collected a particular taxon at a site or in an area, make a collection. This was our approach, for example, with the genus Draba, most species of which we could not reliably identify in the field. Nearly every time we encountered a Draba, we made a collection, which explains why one apparently common species, D. cinerea, is among the most collected on Victoria Island.

Vascular plant species diversity in the Canadian Arctic is correlated with habitat diversity. A large subset of species in the Arctic tend to be dominant and widespread, present wherever suitable habitat occurs; these species are easy to find. On the other hand, many vascular plant species in the Arctic tend to be uncommon on the landscape and occur in microhabitats that do not reflect the dominant vegetation in an area. Examples of microhabitats we encountered on Victoria Island with interesting vascular plant diversity included bird perches (rocks, cliffs), shallow freshwater ponds and south-facing slopes. Locating and searching as many microhabitats as possible results in discovery of the greatest number of species, as we found on Victoria Island. Accordingly, the general locations of our camp sites were chosen by targeting areas that appeared, on topographical maps, to be topographically diverse, ideally including local variation in elevation, aspect, moisture and geology. Ability to survey as many habitats as possible in an area is related to the amount of time available for searching and the diversity of the landscape. The number of days we spent in each area were determined based on our estimate of how long it would take to thoroughly explore the local habitat diversity, though other factors also affected this, such as availability of helicopter support and weather, which greatly affects logistical planning in the Arctic. Exactly where we were able to establish base camps was dependant on suitable areas to land a Twin Otter plane on the tundra in order to establish a camp, the availability of helicopter support for establishing a camp, logistical and financial support for plane and helicopter time, and weather.

The species discovery curves (Fig. 7) show that as the days progressed in each of our study areas, new species continued to be found, because we specifically targeted our searches in new habitats and areas. In most areas studied, the number of new species found either plateaued or approached plateau after several days of local exploration. The large spike in the number of new species recorded on day five in the Oterkvik Point area corresponds to travel to sites by helicopter, including stops at coastal areas where we collected numerous species not present inland in the area. More distant sites visited by helicopter staging from Oterkvik Point (Clouston Bay, Colville Mts.), however, are not included in the diversity count for that area because they are too far away to reasonably be considered as part of the Oterkvik Point region. The spike in the number of new species recorded in the Johansen Bay area on the ninth day in that area is a result of collections gathered during a ca. 16 kilometer (round trip) hike from our camp to the coast. Plateaus in the mid portions of some of the species discovery curves generally correspond to days that were spent processing field collections (i.e., pressing plants, taking tissue samples, recording field notes) made on the previous one or two days. Accordingly, no or few new collections representing species that had not yet been recorded at the site were made on those days because field exploration was limited. Species diversity discovered at the Sinclair Creek site was the lowest among the six intensive study areas because we spent only three days there, the least amount of time spent at any of the sites. Moreover, the total area covered by our brief exploration in the vicinity of Sinclair Creek was 1 km2, compared to the Johansen Bay and Oterkvik Pt. areas, which were 355 km2 and 212 km2, when helicopter sites are taken into account.

Diversity in ecological zones

Bioclimate subzones

Vascular plant biodiversity in the Arctic is correlated with summer warmth, with diversity declining substantially from south to north. A total of 75–150 species is expected in local floras across bioclimate subzone C and 125–250 in subzone D, based on research by Young (1971) and followed by CAVM Team (2003). Although Young (1971) did not explicitly define his concept of “local flora”, his examples indicate that the he was referring to floras of islands, parts of islands (e.g., the Inner Fjord District of Spitzbergen; coastal fringes of Ellesmere Island; the Eureka area of Ellesmere Island), groups of islands (e.g., Franz Josef archipelago), and geographically defined mainland areas like the Boothia and Melville peninsulas. The levels of diversity documented in seven local areas of Victoria Island that may be considered relatively comprehensively documented botanically are within the range of diversity estimated for local floras in subzone D, in which all the sites are located (Boot Inlet: 139 taxa; Cambridge Bay: 183; Johansen Bay: 181; Kuujjua River: 176; the head of Minto Inlet: 173; Oterkvik Point: 127; Ulukhaktok: 194). Subzone D is richer in vascular plant diversity than is subzone C on Victoria Island. A total of 280 taxa are recorded from the subzone D portion of Victoria Island, a level of diversity slightly higher than expected if this area were considered as a local flora. No local or regional areas within subzone C on Victoria Island are comprehensively documented, but the diversity recorded across the subzone (157 taxa) is just slightly higher than the maximum expected by Young (1971) for a local flora within the subzone. Many of the 134 species recorded in subzone D but not in subzone C on Victoria Island reach their known north limits in subzone D, as noted in the annotated checklist.

Comparisons of documented levels of vascular plant diversity among the various bioclimate and ecological zones defined on Victoria Island and with diversity recorded within the subzones elsewhere in the Canadian Arctic provides insight into how complete current documentation of the vascular flora is across the island. Several taxa on the island recorded from both bioclimate subzones C and D are known from single occurrences in subzone C. Although uncommon (or poorly documented) in subzone C on the island, all but one are common and/or known from multiple collections elsewhere in the subzone either in the eastern and northern Arctic (Cystopteris fragilis) or more or less throughout the subzone (western, eastern and northern) (Equisetum arvense subsp. alpestre, Huperzia arctica, Woodsia glabella). Their rareness in subzone C on the island may therefore be a result of collection bias, which seems likely for E. arvense, or lack of appropriate habitat, which seems likely for the fern taxa, which grow on acidic substrates that are uncommon on Victoria Island. The presence of Carex vaginata in subzone C is a borderline occurrence, as the species is known elsewhere in that subzone only from one area of Banks Island. Of the seven species recorded in subzone C but not in subzone D on Victoria Island, four occur elsewhere in subzone D in Canada: Cardamine bellidifolia, which is widespread in several parts of subzone D, and Puccinellia bruggemannii, Ranunculus sabinei and R. sulphureus, which are recorded mostly along the northern edge of subzone D (Aiken et al. 2007). One species is not known from subzone D (or E) elsewhere in Canada (Draba pauciflora), one is known only from one area of subzone D (Saxifraga flagellaris subsp. platysepala, recorded from southern Banks Island), and one (Deschampsia cespitosa subsp. cespitosa) is known only from subzones D and E in Canada (Aiken et al. 2007). The single occurrence of this last taxon on Victoria Island, collected at Washburn Lake, is ca. 1 km north of the subzone C/D boundary, and it may be equally appropriate to consider it to be within subzone D.

There is also considerable variation in levels of vascular plant diversity recorded within subzone C on Victoria Island. For example, within the Nunavut portion of subzone C, lower diversity (101 taxa) is recorded from the northern part of the subzone, here arbitrarily defined as comprising Storkerson Peninsula, the head of and west side of Hadley Bay, and Natkusiak Peninsula, than is recorded from the rest of the subzone in Nunavut. Of the species recorded from the more northerly Nunavut portion of subzone C, 18 are not recorded from the more southerly Nunavut portion of the subzone (Caltha palustris subsp. radicans, Cardamine bellidifolia, Carex nardina, Cerastium arcticum, Chamaenerion latifolium, Eriophorum angustifolium, Micranthes foliolosa, Papaver dahlianum, Pleuropogon sabinei, Potentilla uschakovii, Puccinellia angustata, P. vaginata, P. vahliana, Ranunculus hyperboreus subsp. hyperboreus, R. nivalis, R. sulphureus, Sagina nivalis, Saxifraga flagellaris subsp. platysepala). All but four of these (Cardamine bellidifolia, Micranthes foliolosa, Ranunculus sulphureus and Saxifraga flagellaris subsp. platysepala) are recorded in the Nunavut portion of subzone D on the island. It is therefore likely that the remaining 13 species occur within the southern Nunavut portion of subzone C, but are as yet unrecorded. Reciprocally, there are 43 species recorded in the southern Nunavut portion of subzone C on Victoria Island that are not recorded in the northern Nunavut portion of the subzone (Armeria scabra, Arnica angustifolia subsp. angustifolia, Astragalus richardsonii, Braya thorild-wulffii subsp. glabrata, Carex atrofusca, C. bigelowii subsp. lugens, C. borealipolaris, C. chordorrhiza, C. fuliginosa subsp. misandra, C. maritima, C. saxatilis, C. simpliciuscula subsp. subholarctica, Cassiope tetragona subsp. tetragona, Deschampsia cespitosa subsp. cespitosa, Draba arctica, D. glabella, D. nivalis, D. pauciflora, D. simmonsii, Elymus alaskanus subsp. alaskanus, Equisetum arvense subsp. alpestre, Erigeron eriocephalus, Eriophorum brachyantherum, E. callitrix, Festuca rubra subsp. arctica, Juncus triglumis subsp. albescens, Oxytropis maydelliana, Papaver lapponicum, Potentilla subgorodkovii, Puccinellia arctica, Ranunculus codyanus, R. gmelinii subsp. gmelinii, R. pygmaeus, Salix alaxensis var. alaxensis, S. arctica × S. polaris, S. niphoclada, S. polaris, Saxifraga aizoides, Silene uralensis subsp. arctica, Symphyotrichum pygmaeum, Taraxacum ceratophorum, T. hyparcticum, Tofieldia pusilla, Woodsia glabella). A subset of these are expected to be present within the northern Nunavut portion of the subzone, given their documented occurrences on nearby islands to the north and east (Aiken et al. 2007): Cassiope tetragona subsp. tetragona, Carex fuliginosa subsp. misandra, Taraxacum hyparcticum, Draba nivalis, D. pauciflora, D. simmonsii, Equisetum arvense subsp. alpestre, Ranunculus pygmaeus, Silene uralensis subsp. arctica. Others (Arnica angustifolia, Carex maritima, Draba arctica, D. glabella, Erigeron eriocephalus, Ranunculus codyanus, Taraxacum ceratophorum) that are recorded elsewhere in the Canadian Arctic Archipelago from central to western Melville Island, the eastern islands and the northern Queen Elizabeth Islands, but are apparently absent (if present, they are not yet recorded) from a broad area in the central Archipelago (Aiken et al. 2007), may or may not occur in the northern Nunavut portion of subzone C on Victoria Island; their absence there may be part of the distribution gap. The rest are at the edge of their range and/or reach their northern limit, at least in the western Archipelago, elsewhere on Victoria Island (Aiken et al. 2007); discovery of any of these on northeastern Victoria Island would represent range extensions.

Species are not distributed evenly throughout subzone D across southern Victoria Island. The composition of the vascular flora of the southeastern part of the island differs somewhat from the southwestern part. As a way to quantitatively assess this, we arbitrarily divided the subzone at Wellington Bay. We found that 178 species are known from both east and west of Wellington Bay, 216 are recorded from east of the bay and 224 from west of the bay. These differences are likely due to a combination of the historical biogeography of the region, in that a subset of species present on the southwestern part of the island, such as those with western or Beringian distributions that are at the edges of their ranges on western and southwestern Victoria Island, are likely absent on the southeastern part, and collection bias, in that some species that are present have not yet been documented in areas east or west of the bay. Species recorded from subzone D on southwestern but not southeastern Victoria Island that are not known from nor expected to occur on the southeastern part of the island, given knowledge of their broader distributions (Aiken et al. 2007), are Arenaria longipedunculata, Artemisia borealis subsp. richardsoniana, Artemisia hyperborea, Carex petricosa subsp. petricosa, Draba oligosperma, Elymus alaskanus, Erigeron compositus, Eurybia sibirica, Gentianella propinqua subsp. propinqua, Halerpestes cymbalaria, Hedysarum americanum, Linum lewisii, Lomatogonium rotatum subsp. rotatum, Mertensia drummondii, Oxytropis varians, Parnassia kotzebuei, Parrya nudicaulis, Puccinellia banksiensis, Salix alaxensis var. alaxensis, Salix niphoclada, Silene ostenfeldii, Suaeda calceoliformis and Taraxacum scopulorum. Discovery of any of these on southeastern Victoria Island would represent range extensions. Some that require acidic substrates (Andromeda polifolia, Carex glacialis, Luzula wahlenbergii) may be rare or absent. Species known from southwestern Victoria Island that are not yet recorded but likely to exist on the southeastern part of the island, given their broader distributions across the Canadian Arctic Archipelago (Aiken et al. 2007), are Calamagrostis purpurascens, C. stricta subsp. groenlandica, Campanula uniflora, C. microglochin, Cerastium arcticum, Potentilla anserina subsp. groenlandica, P. × prostrata and Salix arctophila. Species recorded in subzone D on southeastern but not southwestern Victoria Island that are not expected to be present on the southwestern part of the island, based on their known distributions (Aiken et al. 2007), include Anthoxanthum monticola subsp. monticola, Cerastium regelii, Draba micropetala, D. norvegica, Pleuropogon sabinei and Sagina caespitosa. Those expected to be present on the southwestern part of the island but not yet recorded there, based on their known distributions elsewhere on the island and/or across the Archipelago (Aiken et al. 2007), include Antennaria monocephala subsp. angustata, Arctous alpina, Carex chordorrhiza, C. nardina, Chrysosplenium tetrandrum, Crucihimalaya bursifolia, Petasites frigidus subsp. frigidus, Poa pratensis subsp. colpodea, Puccinellia vahliana, Ranunculus codyanus, Ranunculus hyperboreus subsp. hyperboreus, Sagina nivalis, Salix polaris and Tofieldia coccinea. Some species recorded from the southeastern part of the island are rare, known from a single collection, which, in a subset of cases, are the only records for the Canadian Arctic Archipelago: Bromus pumpellianus, Castilleja pallida var. caudata, Eriophorum russeolum subsp. albidum, Erysimum coarctatum, Pulsatilla nuttalliana, Rubus chamaemorus, Salix ovalifolia var. ovalifolia, Salix planifolia, Senecio lugens and Stuckenia filiformis.

Northwest territories ecological regions

Our data indicate very low documented species diversity for most of the Northwest Territories ecological regions. With the exception of the Prince Albert Coastlands Low Arctic North ecoregion, which includes Ulukhaktok and the areas around Minto Inlet we intensively surveyed in 2010 (Kuujjua River, head of Minto Inlet and Boot Inlet) and that several other collectors have visited, low recorded diversity is due to collection bias rather than reflecting true levels of vascular plant diversity. Aside from our 2010 efforts, there has been no attempt to comprehensively document local floras at sites/areas within the ecological regions, and most have only been cursorily explored. For example, in the East Prince Albert Plain Mid-Arctic Ecoregion, spanning 9,866 km2, only six species are known, all recorded from one site, by S. Edlund, on the east side of Richard Collinson Inlet. Within the West Prince Albert Upland Mid-Arctic Ecoregion collections representing 37 taxa were been made by M. Oldenburg at a single site, “Oldenburg Lake”, all of which are newly reported here. In the Shaler Mountains Mid-Arctic Ecoregion 51 taxa are recorded, in the Wollaston Peninsula Mid-Arctic Ecoregion just 29 taxa are recorded, and collections representing 76 taxa have been made in the Tahiryuak Upland Mid-Arctic Ecoregion. Considerable field work will be needed to accurately document levels of vascular plant diversity in most of these regions, which may be considered underexplored botanically.

Conclusion

This study has substantially increased our understanding of the diversity and distribution of the vascular plant flora of Victoria Island. The results represent a new baseline of knowledge on which continued exploration of the flora of the island can build. We have provided documentation of several taxa new to the island and increased knowledge of the spatial distribution of taxa across the island. Study of existing herbarium material, which was greatly facilitated by recent mass-digitization efforts at several institutions, revealed a large number of occurrence records that have been overlooked in previous efforts to document the vascular flora of Vascular Island. Nearly 50 taxa on the island are rare, known by three or fewer collections. Although more than 7000 unique collections of vascular plants have been made on Victoria Island, many areas remain unexplored or poorly explored botanically. Numerous species that are expected to occur within bioclimate subzones C on the island have not yet been recorded there, while many species reach their northern limits in bioclimate subzone D on the island. We expect (and hope) that many new collections of vascular plants will be gathered over the coming years, particularly related to CHARS research activity in the Cambridge Bay area, on southeastern Victoria Island and across the entire island, and that the information on the distribution and diversity of vascular plant diversity on the island presented here will help guide future documentation efforts. The complete, specimen-based dataset published here will allow future workers to generate updated distribution maps including new occurrence records. We strongly encourage all researchers conducting botanical or plant-related ecological research on Victoria Island and throughout the Canadian Arctic to document species occurrences with specimens, and to deposit the material in one or more publically accessible herbaria, so that the collections may contribute to the centuries long mission to document Arctic biodiversity.

Annotated checklist

Key to major groups

1 Plants not producing flowers or seeds, reproducing by spores 2
Plants producing flowers and seeds 4
2 Stems conspicuously jointed, bearing at each node a whorl of small, scale-like leaves united at the base Equisetaceae
Stems not conspicuously jointed, bearing green leaves or leaf-like structures, leaves not whorled, usually not scale-like 3
3 Leaves lanceolate to triangular, not divided; sporangia axillary Lycopodiaceae
Leaves (fronds) pinnately divided; sporangia borne on lower surface of leaves Polypodiales
4 Leaves usually parallel-veined; parts of the perianth usually in threes or sixes; seeds with a single cotyledon Monocots
Leaves usually net-veined; parts of the perianth usually in fours or fives; seeds with two cotyledons Eudicots

Key to Polypodiales [adapted from Porsild (1964) and Porsild and Cody (1980)]

1 Fronds once pinnate, lower pinnae sometimes notched or toothed; sori with a divided, hair-like indusium Woodsiaceae
Fronds 2–3 pinnate or pinnatifid; sori with a hooded lateral indusium, or without indusia 2
2 Sori with a distinct lateral indusium; fronds thin, somewhat translucent; stipe thin, fragile, more or less translucent, easily disarticulated from a lateral rhizome Cystopteridaceae
Sori without an indusium; fronds stout; stipe stout, not fragile, firmly attached to a stout rootstock Dryopteridaceae

Key to Monocots

1 Perianth absent or inconspicuous and of bracts, scales or bristles 2
Perianth present, in two distinct whorls 4
2 Flowers not enclosed in or subtended by bracts, scales or bristles; plants aquatic; leaves submersed or floating; stipules present, adnate to the blade for 2/3 to nearly the entire length of the stipule; inflorescences submersed Potamogetonaceae
Flowers enclosed in or subtended by bracts, scales or bristles; plants usually terrestrial, rarely aquatic; leaves erect, rarely floating (Arctophila, Pleuropogon); stipules absent; inflorescences never submersed if plants aquatic 3
3 Stems round, hollow between nodes; leaves 2-ranked; leaf sheaths usually open, sometimes closed; anthers attached at the middle; fruit a caryopsis Poaceae
Stems triangular or round, solid; leaves 3-ranked; leaf sheaths closed; anthers attached at the base; fruit an achene Cyperaceae
4 Plants rootless and leafless, mycotrophic; flowers zygomorphic Orchidaceae
Plants with roots and leaves, autotrophic; flowers actinomorphic 5
5 Perianth conspicuous, deciduous; tepals white, yellowish-green, greenish, pinkish cream or deep crimson; leaves equitant (having the base folded and partly enclosing the leaf above), laterally flattened Tofieldiaceae
Perianth relatively inconspicuous, persistent; tepals green to brown or purplish black; leaves not equitant, dorsi-ventrally flattened or round Juncaceae

Key to Eudicots

1 Plants aquatic 2
Plants terrestrial 4
2 Leaf blades entire Plantaginaceae (Hippuris)
Leaf blades finely divided 3
3 Leaves in whorls; flowers unisexual, 4-merous, petals lacking or inconspicuous and pinkish Haloragaceae
Leaves alternate; flowers bisexual, 5-merous, petals conspicuous, yellow or white Ranunculaceae (Ranunculus)
4 Plants with woody or partly lignified creeping or erect stems (shrubs or sub-shrubs) 5
Plants herbaceous 9
5 Leaves finely divided or lobed Asteraceae (Artemisia)
Leaves not divided or lobed, the margins at most crenulate or serrate 6
6 Petals absent; flowers arranged in catkins 7
Petals present; flowers variously arranged, not in catkins 8
7 Plants monoecious; fruits 2-winged samaras, 1-seeded, seeds lacking hairs Betulaceae
Plants dioecious; fruits capsules, many seeded, seeds bearing a tuft of hairs Salicaceae
8 Stamens 10 or fewer Ericaceae (Andromeda , Arctous , Cassiope , Empetrum , Rhododendron , Vaccinium)
Stamens 50+ Rosaceae (Dryas)
9 Flowers arranged in dense heads on a common receptacle (the inflorescence having the appearance of a single flower) Asteraceae
Flowers arranged variously, but not on a common receptacle 10
10 Flowers with a single perianth 11
Flowers with a double perianth 15
11 Leaves whorled Rubiaceae
Leaves not whorled 12
12 Leaves divided or deeply lobed Ranunculaceae (Anemone , Anemonastrum , Pulsatilla)
Leaves not deeply lobed or divided 13
13 Stipules present, fused and sheathing (ocrea) Polygonaceae
Stipules absent 14
14 Annuals; fruit a utricle Amaranthaceae
Perennials; fruit a capsule Saxifragaceae (Chrysosplenium)
15 Petals fused 16
Petals distinct, not fused 23
16 Stems scapose 17
Stems leafy 20
17 Scape 1-flowered; plants carnivorous (leaves sticky and glandular, trapping and digesting insects) Lentibulariaceae
Scape several-flowered; plants not carnivorous 18
18 Inflorescences simple, spicate Plantaginaceae (Plantago)
Inflorescences compound 19
19 Inflorescences umbels; fruits capsular Primulaceae
Inflorescences dense hemispheric heads of scorpioid cymes; fruits dry, enclosed by persistent calyces Plumbaginaceae
20 Leaves alternate 21
Leaves opposite 22
21 Inflorescence a single flower; corolla campanulate; ovary inferior; fruit a capsule Campanulaceae
Inflorescences corymbose; corolla tubular or funnel-form; ovary superior; fruit an aggregate of nutlets Boraginaceae
22 Flowers actinomorphic Gentianaceae
Flowers zygomorphic Orobanchaceae
23 Cauline leaves opposite 24
Cauline leaves alternate, or plants with a basal rosette 26
24 Plants annual Montiaceae
Plants perennial 25
25 Ovary inferior Onagraceae (Epilobium)
Ovary superior Caryophyllaceae
26 Flowers strongly zygomorphic Fabaceae
Flowers actinomorphic or slightly zygomorphic 27
27 Pistils 2-several 28
Pistil 1 31
28 Perianth and androecium attached to the receptacle below the ovary (hypogynous) 29
Perianth and androecium fused at the base to form a hypanthium (perigynous) 30
29 Staminodes present Celastraceae
Staminodes absent Ranunculaceae
30 Stipules present Rosaceae (Potentilla, Rubus)
Stipules absent Saxifragaceae (Micranthes)
31 Petals 4 32
Petals 5 34
32 Ovary inferior Onagraceae (Chamaenerion)
Ovary superior 33
33 Sepals 4; stamens 6, in two distinct whorls, outer ones short, inner ones long; ovary 2-locular Brassicaceae
Sepals 2; stamens many, not in two distinct whorls; ovary 1-locular Papaveraceae
34 Ovary 1-locular Saxifragaceae (Saxifraga)
Ovary 2-several-locular 35
35 Leaves basal (or appearing so), blades ovate, broadly ovate, elliptic, orbiculate, round or subreniform; petals green, greenish white, yellowish white, white, pinkish, or reddish Ericaceae (Orthilia, Pyrola)
Leaves cauline, blades linear, linear-lanceolate or linear-oblanceolate; petals usually blue, sometimes whitish Linaceae

Lycopods

Lycopodiales

Lycopodiaceae [1/1]

Huperzia Bernh. [1]

Huperzia arctica (Grossh. ex Tolm.) Sipliv. (H. selago subsp. arctica (Grossh. ex Tolm.) Á.Löve & D.Löve, Lycopodium selago subsp. arcticum Grossh. ex Tolm.), Fig. 8A–Arctic fir clubmoss | Circumpolar?

Figure 8. 

Species distribution maps. Lycopodiaceae: A Huperzia arctica. Equisetaceae: B Equisetum arvense subsp. alpestre C Equisetum scirpoides D Equisetum variegatum subsp. variegatum. Cystopteridaceae: E Cystopteris fragilis. Woodsiaceae: F Woodsia glabella. Dryopteridaceae: G Dryopteris fragrans. Tofieldiaceae: H Tofieldia coccinea I Tofieldia pusilla. Potamogetonaceae: J Stuckenia filiformis K Stuckenia vaginata. Orchidaceae: L Corallorhiza trifida.

Previously recorded from Ulukhaktok (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Richardson I. and Johansen B. (conf.). Newly recorded from Ferguson L. [Tahiryuaq] and Mukta [?] L.; the latter site is not mapped as its location is unclear. The Ferguson L. site was noted as being more acidic than other sites in the areas visited in 2014, and the taxon was associated with ericaceous shrubs. The taxon was observed and photographed in 2015 by J. Wagner at the base of the hills above Long Point (69.1265, -105.4638) west of Cambridge Bay (image! BAB and JMS); a voucher from this locality is needed. Elsewhere in the Canadian Arctic known from Baffin, Coats, Devon, Ellesmere, Melville, Prince Patrick, Somerset and Southampton islands and mainland sites (Porsild and Cody 1980, Cody and Britton 1989, Cody et al. 1989, Korol 1992, Aiken et al. 2007, Dignard 2013d, Saarela et al. 2013, Saarela et al. 2017b). Recognition of H. arctica as distinct from the boreal H. selago (L.) Bernh. ex. Schrank & Mart. follows Elven et al. (2011), Gilman and Testo (2015) and Dignard (2013d). Wagner and Beitel (1993) did not map H. selago s.l. as occurring in the Canadian Arctic, despite numerous records from the region known prior to their treatment.

NORTHWEST TERRITORIES. Ulukhaktok: Edlund 476, 745 (CAN), Porsild 17234, 17235 (CAN). NUNAVUT. Ferguson L. [Tahiryuaq]: Bennett et al. 14-0432 (BABY). Johansen B.: Gillespie et al. 7958 (CAN, O). Mukta [?] L.: Hainault 2124 (DAO).

Monilophytes

Equisetales

Equisetaceae [1/3]

Equisetum L. [3]

Key to Equisetum [adapted from Porsild and Cody (1980) and Hauke (1993)]:

1 Stems annual (persisting one year or less), bearing whorls of branches; cones terminal on brown unbranched reproductive stems or green branched stems; cone apex rounded E. arvense subsp. alpestre
Stems evergreen (persisting more than one year), unbranched or forking; cones terminal on green stems; cone apex pointed 2
2 Teeth 3 per sheath; stem ridges 6; stems inclined and tortuous E. scirpoides
Teeth 3–12 per sheath; stem ridges same number as teeth; stems stiff and straight E. variegatum subsp. variegatum

Equisetum arvense subsp. alpestre (Wahlenb.) Schönsw. & Elven, Figs 8B, 9A–Alpine field horsetail | Circumpolar-alpine

Figure 9. 

A Equisetum arvense subsp. alpestre strobilus (left) and habit (right), Gillespie et al. 10109 B Equisetum variegatum subsp. variegatum habit, Gillespie et al. 8499 C Cystopteris fragilis habit, Gillespie et al. 9990 D Dryopteris fragrans habit, Johansen Bay, 18 July 2008 E Woodsia glabella habit F Woodsia glabella habitat G Tofieldia coccinea inflorescences, Kuujjua River, NT, 18 July 2010 H Tofieldia coccinea habit, Gillespie et al. 9749. Photos A, C by L.J. Gillespie B, D, G by R.D. Bull H by J.M. Saarela and E, F by B.A. Bennett.

Previously recorded from Cambridge Bay, Ferguson L., the head of Minto Inl. (Porsild obs., conf.), Mt. Pelly, inland from the head of Prince Albert S., Ulukhaktok (Porsild obs., conf.) and Walker B. (Porsild obs.) (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally reported it from Johansen B. (conf.), Richardson I. and Surrey L. Newly recorded from Clouston B., Greiner L., Kuujjua R., Richard Collinson Inl., Sinclair Cr. and “Trunsky L.” Taxonomy follows Elven et al. (2011), who recognize northern plants as subsp. alpestre and more southerly ones as subsp. arvense. Their distributions have not been mapped for North America. Equisetum arvense s.l. is widespread across the Arctic mainland (Porsild and Cody 1980, Korol 1992, Cody et al. 2003, Dignard 2013c, Bennett 2015) and the Archipelago, where recorded from Axel Heiberg, Baffin, Banks, Devon, Ellesmere, King William, Somerset, Southampton and western Melville I. (Aiken et al. 2007). The apparent absence from the northeastern part of Victoria I. may be part of a broader distribution gap in the central Queen Elizabeth Islands and adjacent Prince of Wales I. (Aiken et al. 2007), assuming the taxon has not simply been overlooked in those areas.

NORTHWEST TERRITORIES. Boot Inl.: Edlund 576 (CAN), Gillespie et al. 9576 (ALA, CAN, MT, O), 9601 (ALA, CAN, O). Kuujjua R.: Gillespie et al. 9797 (CAN, O), 9814 (CAN). Minto Inl. (head): Edlund 136 (CAN), Gillespie et al. 10051 (ALA, CAN, MT, O, UBC, WIN), 10109 (ALTA, ari, CAN, MO, O, UBC, US, UTC, WIN), 10181, 10226 (CAN). Richard Collinson Inl.: Edlund 174 (CAN). Ulukhaktok: Edlund 481, 829 (CAN). NUNAVUT. Cambridge Bay: Edlund & Argus 12863 (CAN), Stephens 1100 (CAN, KANU). Clouston B.: Gillespie et al. 7719, 7757 (CAN). Ferguson L. [Tahiryuaq]: Hainault 2140 (DAO). Greiner L.: Ponomarenko VI-141, VI-203K (CAN). Johansen B.: Gillespie et al. 7935 (ALA, CAN, MT, O, UBC), 7961 (CAN, O), 8107 (CAN, O). Ovayok TP: Stephens 1066 (CAN, KANU), 1109 (KANU), 1174 (CAN). Prince Albert S. (head): Edlund & Argus 12812 (CAN). “Trunsky L.”: Bennett et al. 14-0395 (BABY), 14-0540 (CAN).

Equisetum scirpoides Michx., Fig. 8C–Dwarf scouring-rush | Circumboreal–polar

The only previous record (unconfirmed) for Victoria I. is from Johansen B. (Thannheiser et al. 2001). Newly recorded from Boot Inl., where the species grew in a snowbed community at the base of a north-facing cliff above a lake, and the Kuujjua R. area, where it was gathered from the shore of a small round lake northeast of “Fish L.”. Elsewhere in the Canadian Arctic recorded from scattered sites on southern Baffin, Banks, Coats, King William and Southampton islands (Aiken et al. 2007) and the mainland (Porsild and Cody 1980, Cody et al. 1984a, Cody and Britton 1989, Cody et al. 1989, Dignard 2013c, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES: Boot Inl.: Gillespie et al. 9616 (ALA, CAN). Kuujjua R.: Gillespie et al. 9773 (CAN).

Equisetum variegatum Schleich. subsp. variegatum, Figs 8D, 9B–Variegated scouring-rush | Circumpolar-alpine

Previously recorded from Anderson B., Cambridge Bay, C. Wollaston, Ferguson L., Hadley B., Kuujjua R., the head of Minto Inl., Mt. Pelly, Namaycush L., Natkusiak P., the head of Prince Albert S. (Porsild obs.), Richard Collinson Inl., Storkerson P., Tahoe L. (Porsild obs.) and Ulukhaktok (Porsild 1955, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.) and Richardson I. Newly recorded from Albert Edward B., Boot Inl., Greiner L., Mt. Lady Pelly, Oterkvik Pt. and Sinclair Cr. Widespread throughout the Canadian Arctic islands, except those that comprise bioclimate subzone A, and across the mainland (Porsild and Cody 1980, Korol 1992, Aiken et al. 2007, Dignard 2013c, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9588 (CAN). C. Wollaston: Edlund 28 (CAN). Kuujjua R.: Edlund 643 (CAN), Gillespie et al. 9826 (ALA, ari, CAN, O, UBC). Minto Inl. (head): Edlund 611, 78 (CAN), Gillespie et al. 10073 (ALA, CAN, MT, O, UBC), 9484 (CAN). Natkusiak P.: Edlund 112, 160 (CAN). Richard Collinson Inl.: Edlund 175 (CAN). Ulukhaktok: Edlund 753, 802 (CAN), Porsild 17796 (CAN). NUNAVUT. Albert Edward B.: Ponomarenko VI-260 (CAN). Anderson B.: Edlund & Argus 12723 (CAN). Cambridge Bay: Bennett 13-0558 (BABY, chars), 13-0619 (ALA), Gillespie et al. 8499 (CAN), Gould s.n. (ALA), Polunin s.n. (CAN). Ferguson L. [Tahiryuaq]: Hainault 2062 (DAO). Greiner L.: Ponomarenko VI-133A (CAN). Hadley B.: Edlund 91, 129, s.n. (CAN). Johansen B.: Gillespie et al. 8029 (CAN, MT, O). Mt. Lady Pelly [Amaaqtuq]: Hainault 1842 (DAO). Ovayok TP: Stephens 1066A, 1175 (CAN). Namaycush L.: Edlund 13 (CAN, US). Natkusiak P.: Edlund 343 (CAN). Oterkvik Pt.: Gillespie et al. 7505 (ALA, CAN, O), Gillespie et al. 7688 (CAN). Sinclair Cr.: Gillespie et al. 8260 (CAN), 8356 (CAN). Storkerson P.: Edlund 213, 285, 299 (CAN).

Polypodiales

Cystopteridaceae [1/1]

Cystopteris Bernh. [1]

Cystopteris fragilis (L.) Bernh., Figs 8E, 9C–Fragile fern | Cosmopolitan

Previously recorded from Cambridge Bay, Ferguson L., the head of Minto Inl., Mt. Pelly, the head of Prince Albert S. (Porsild obs.), Richard Collinson Inl., Ulukhaktok, Walker B. and Washburn L. (Porsild obs.) (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.) and Richardson I. Newly recorded from Boot Inl., Greiner L., Kuujjua R. and Oterkvik Pt. Elsewhere in the Canadian Arctic recorded from Axel Heiberg, Banks, Baffin, Coasts, Devon, Ellesmere, King William, Somerset and Southampton islands and across the mainland (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Cody et al. 2003, Cody and Reading 2005, Aiken et al. 2007, Dignard 2013a, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9596 (ALA, CAN, MT, O), 9608, 9639, 9690 (CAN). Kuujjua R.: Gillespie et al. 9820 (CAN, O), 9851 (CAN), 9990 (ALA, CAN, O). Minto Inl. (head): Gillespie et al. 10216 (CAN, O), 10277 (ari, CAN, O), Porsild 17351 (CAN). Richard Collinson Inl.: Stretton 193 (DAO). Ulukhaktok: Edlund 804, 844 (CAN), Porsild 17230 (CAN), Saarela & Bull 1485 (CAN, O). Walker B.: Porsild 17479 (CAN). NUNAVUT. Ferguson L. [Tahiryuaq]: Jones & Hainault 3 (DAO). Greiner L.: Ponomarenko VI-046, VI-192, VI-285 (CAN). Johansen B.: Gillespie et al. 7962 (ALA, CAN, O), 8167 (CAN). Ovayok TP: Gillespie et al. 8421 (CAN, UC), Stephens 1171 (CAN), 1283 (CAN, KANU, 2 sheets). Oterkvik Pt.: Gillespie et al. 7530 (CAN, UC, UTC).

Woodsiaceae [1/1]

Woodsia R.Br. [1]

Woodsia glabella R.Br., Figs 8F, 9E, F–Smooth woodsia | Circumpolar–alpine

Previously recorded from Byron B., Cambridge Bay, Ferguson L., Hadley B., the head of Minto Inl., Mt. Pelly, the head of Prince Albert S. (Porsild obs.), Ulukhaktok and Walker B. (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.), Richardson I. and Surrey L. Newly recorded from Greiner L., Kuujjua R., Mt. Lady Pelly, Oterkvik Pt. and an inland site on south-central Victoria I. north of Byron B. Elsewhere in the Canadian Arctic recorded from Axel Heiberg, Baffin, Banks, Coats, Devon, Ellesmere, King William and Southampton islands and across the mainland (Porsild and Cody 1980, Korol 1992, Cody et al. 2003, Aiken et al. 2007, Dignard 2013e, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Kuujjua R.: Gillespie et al. 9867 (ALA, CAN, O). Minto Inl. (head): Gillespie et al. 9446, 10043 (CAN), Porsild 17352 (CAN). Ulukhaktok: Edlund 720, 721, 758, 794 (CAN), Porsild 17232, 17233 (CAN). Walker B.: Porsild 17480 (CAN). NUNAVUT. Byron B.: Dushenko 24 (UVIC). Cambridge Bay: Bennett et al. 13-0200 (BABY, chars), Washburn 12 (CAN). Ferguson L. [Tahiryuaq]: Bennett et al. 14-0426 (DAO), Hainault 1954 (DAO), Jones 2 (DAO). Greiner L.: Ponomarenko VI-047 (CAN). Hadley B.: Edlund 99 (CAN). Johansen B.: Gillespie et al. 7902, 7931 (CAN), 8141 (CAN, MT). Mt. Lady Pelly [Amaaqtuq]: Hainault 1838 (DAO). Ovayok TP: Gillespie et al. 7604 (CAN), 8423 (CAN, O), Gould s.n. (ALA), Stephens 1160, 1172 (CAN). Oterkvik Pt.: Gillespie et al. 7813 (CAN). South-central Victoria I.: Edlund & Argus 12875 (CAN).

Dryopteridaceae [1/1]

Dryopteris Adans. [1]

Dryopteris fragrans (L.) Schott, Figs 8G, 9D–Fragrant wood fern | European (NE)–Asian–amphi-Beringian–North American (N)

Previously recorded from Ulukhaktok and Ferguson L. (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.), Richardson I. and Surrey L. Samples from Johansen Bay were included in a population genetic study of the species, in which high genetic variation among Arctic populations was found (Bouchard et al. 2017). Its restricted distribution on Victoria I. is likely due to its preference/requirement for acidic substrates. Elsewhere in the Canadian Arctic recorded from Banks, Baffin, Ellesmere and Southampton islands and numerous mainland sites (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Cody and Reading 2005, Aiken et al. 2007, Dignard 2013b, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Ulukhaktok: Bandringa 342 (CAN, UBC), Dutilly 18660 (MT), Edlund 843 (CAN), Porsild 17231 (CAN). NUNAVUT. Ferguson L. [Tahiryuaq]: Hainault 1955 (DAO). Johansen B.: Gillespie et al. 7901 (ALA, BABY, CAN, MT, O, UBC), 7986 (ALA, CAN, MT, O), 8024 (CAN, O), 8139 (ALA, CAN, O).

Monocots

Alismatales

Tofieldiaceae [1/2]

Tofieldia Hudson [2]

Key to Tofieldia [adapted from Packer (2002)]

1 Bracts deeply 3-lobed; bracteoles absent; tepals white, cream, yellowish white or sometimes greenish white; capsules 2.5–3 mm; seeds 0.6–0.8 mm T. pusilla
Bracts ovate, margins ± entire (sometimes absent distally); bracteoles 3-lobed; tepals white or pale pink, often tinged pink to deep purplish; capsules 2–2.3 mm; seeds ca. 1 mm T. coccinea

Tofieldia coccinea Richardson, Figs 8H, 9G, H–Northern tofieldia | Asian (N/C)–amphi-Beringian–North American (N)

Previously recorded from Ulukhaktok and Walker B. (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from the head of Minto Inl. (conf.) and Johansen B. (conf.). Newly recorded from Boot Inl. and Kuujjua R. Elsewhere in the Canadian Arctic recorded from one site on southern Banks I., Baffin and Devon islands and scattered mainland sites (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Cody and Reading 2005, Aiken et al. 2007, Gauthier 2013, Saarela et al. 2013, Saarela et al. 2017b). Both species may occur sympatrically, but T. coccinea tends to occur in drier sites (moist to dry) than T. pusilla (moist to wet).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9671 (CAN). Kuujjua R.: Gillespie et al. 9749 (ALA, CAN, O), 9809 (CAN, O), 9811 (ALA, ari, CAN, O). Minto Inl. (head): Gillespie et al. 10108 (CAN, MT), 10159 (CAN, O, UBC). Ulukhaktok: Edlund 475, 743 (CAN), Porsild 17266, 17267, 17268 (CAN). Walker B.: Porsild 17489 (CAN). NUNAVUT. Johansen B.: Gillespie et al. 7941a (ALA, CAN, MT, O, UBC), 7959a (CAN, O).

Tofieldia pusilla (Michx.) Pers., Fig. 8I–Small tofieldia | Circumpolar–alpine

Previously recorded from Ulukhaktok and Walker B. (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007) and newly recorded from Boot Inl., Ferguson L., Johansen B., Kuujjua R., the head of Minto Inl., Mt. Lady Pelly, Mt. Pelly, Oterkvik Pt., the head of Prince Albert S. and an inland site east thereof, Richard Collinson Inl. and Sinclair Cr. The site inland from the head of Richard Collinson Inl. is a northern range extension for the species in Canada. Elsewhere in the Canadian Arctic recorded from Baffin and Southampton islands and several mainland sites (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Cody and Reading 2005, Aiken et al. 2007, Gauthier 2013, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9590 (ALA, CAN, O). Kuujjua R.: Gillespie et al. 9804 (ari, CAN). Minto Inl. (head): Edlund 157 (CAN), Gillespie et al. 9477 (CAN, O). Prince Albert S. (head): Edlund 376 (CAN), Edlund & Argus 12819 (CAN). Richard Collinson Inl.: Edlund 674 (CAN). Ulukhaktok: Edlund 449, 744 (CAN), Oldenburg 45-1598 (CAN), Porsild 17269 (CAN). Walker B.: Oldenburg 45-1507 (CAN), Porsild 17490 (CAN). NUNAVUT. Ferguson L. [Tahiryuaq]: Bennett et al. 14-0429 (CAN), Hainault 2069, 2091 (DAO), Johansen B.: Gillespie et al. 7941b (CAN), 7959b (CAN, O), 8003 (ALA, CAN, MT, O, UBC), 8128 (ALA, CAN, MT, O). Mt. Lady Pelly [Amaaqtuq]: Jones & Hainault 7, 1844 (DAO). Ovayok TP: Gillespie et al. 8432 (ALA, CAN, O). Oterkvik Pt.: Gillespie et al. 7469 (CAN), 7668 (ALA, CAN, MT, O). Sinclair Cr.: Gillespie et al. 8231 (ALA, CAN, MT, O, UBC).

Potamogetonaceae [1/2]

Stuckenia Börner [2]

Key to Stuckenia [adapted from Haynes and Hellquist (2000) and Kaplan (2008)]

1 Leaf sheaths closed and tubular at base (connate) at least when young; stems freely branching proximally, sparsely branching distally; stipules with distinct ligules to 20 mm, especially on distal stipules; summit of midstem stipules tight to stem, about the ± same width as stem; fruit 2–3 mm S. filiformis
Leaf sheaths open at base, even when young, often with shortly overlapping edges (convolute); stems freely branching proximally to distally; stipules without ligules or ligules to 2 mm on distal stipules; summit of midstem stipules inflated at least 2 times width of stem; fruit 3–3.8 mm S. vaginata

Stuckenia filiformis (Pers.) Börner (Potamogeton filiformis Pers., S. filiformis var. borealis (Raf.) H.St.John, S. filiformis subsp. alpina (Blytt) R.R.Haynes, Les & M.Král), Fig. 8J–Slender-leaved pondweed | Circumboreal–polar

Newly recorded for Victoria I., where discovered growing in a small lake (shallow water with Hippuris lanceolata) near Greiner L. in 2016. The site marks the northern edge of the species’ range in the central Canadian Arctic. Elsewhere in the Canadian Arctic Archipelago known only from Sylvia Grinnell Territorial Park on Baffin I. and two sites on Southampton I. (Calder 1951, Aiken et al. 2007). On the mainland Arctic known from the lower Coppermine R. area, a few sites along western Hudson Bay and northern Quebec (Korol 1992, Aiken et al. 2007, Garneau 2013, Saarela et al. 2017b).

NUNAVUT. Greiner L.: Ponomarenko CB52 (CAN).

Stuckenia vaginata (Turcz.) Holub (Potamogeton vaginatus Turcz., S. subretusa (Hagstr.) Holub), Fig. 8K–Big-sheathed pondweed | European (N)–Asian (C-NE)–North American

Known from a single locality in the vicinity of Johansen B., discovered in 2008; see Gillespie et al. (2015) for additional details, including photographs. This is the only record for the Canadian Arctic Archipelago. Elsewhere in the Canadian Arctic known from a few collections from the mainland Northwest Territories and southeastern Nunavut (Porsild 1950b, Porsild and Cody 1980, Cody et al. 2003, Saarela et al. 2013, Saarela et al. 2017b).

NUNAVUT. Johansen B.: Gillespie et al. 8048 (ALA, ALTA, BABY, CAN, MT, O, UBC, US).

Asparagales

Orchidaceae [1/1]

Corallorhiza Gagnebin [1]

Corallorhiza trifida Châtel., Fig. 8L–Early coralroot | Circumboreal-polar

Known from a single collection we made in 2008 at Johansen B.; see details in Gillespie et al. (2015), which includes photographs. Elsewhere in the Canadian Arctic recorded from a few sites on Baffin I. and across the mainland (Porsild and Cody 1980, Aiken et al. 2007, Saarela et al. 2013, Gillespie et al. 2015, Saarela et al. 2017b).

NUNAVUT. Johansen B.: Gillespie et al. 8093 (CAN).

Poales

Juncaceae [2/7/8]

Key to Juncaceae

1 Capsules many-seeded; leaves glabrous, sheaths open Juncus
Capsules 3-seeded; leaves hairy, sheaths closed Luzula

Juncus L. [4/5]

Key to Juncus [adapted from Porsild and Cody (1980), Brooks and Clemants (2002) and Kirschner (2002c)]

1 Inflorescences lateral cymes, sympodial; bracts erect, terete, appearing to be continuation of culms; bracteoles 2, at base of perianth; basal leaves bladeless, cauline leaves absent; flowers borne singly, not in heads (J. arcticus) 2
Inflorescences terminal panicles or racemes of several heads or a single terminal head, sympodial or monopodial; bracteoles absent at base of perianth; basal leaves (at least some) usually with blade, cauline leaves present or absent; flowers in multiflowered heads 3
2 Flowers usually 2–5 per inflorescence; bract c. ¼–1/8 of culm J. arcticus subsp. arcticus
Flowers 3–10 per inflorescence; bract 1/7–1/10 of culm J. arcticus subsp. alaskanus
3 Plants strongly rhizomatous, culms solitary; inflorescences of 1–3(–5) heads, each 2–10-flowered; tepals lanceolate, 4.5–6.6 mm J. leucochlamys
Plants cespitose, culms clustered; inflorescences single heads, each 1–2(–4)-flowered; tepals oblong or oblong-lanceolate, 2.5–5 mm 4
4 Primary bract much longer than inflorescence; capsule apex retuse; filaments 1–1.5 mm J. biglumis
Primary bract nearly equal to or shorter than inflorescence; capsule apex obtuse, mucronate; filaments 2.5–4 mm J. triglumis subsp. albescens

Juncus arcticus Willd. subsp. arcticus, Fig. 10A–Arctic rush | North American (NE)–amphi-Atlantic–European (N)–Asian (NW)

Figure 10. 

Species distribution maps. Juncaceae: A Juncus arcticus subsp. arcticus B Juncus arcticus subsp. alaskanus C Juncus biglumis D Juncus leucochlamys E Juncus triglumis subsp. albescens F Luzula confusa G Luzula nivalis H Luzula wahlenbergii.

Juncus arcticus s.l. was previously recorded from Cambridge Bay, the head of Minto Inl. and Ulukhaktok (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). We follow the taxonomy proposed by Kirschner (2002a), who recognized three subspecies (two in North America), with the caveat that assigning individuals to a taxon was sometimes difficult for Victoria I. material. These intermediate individuals may represent transitions between the subspecies (Elven et al. 2011), whose main distributions come together in the central Canadian Arctic. Subspecies arcticus is recorded from Cambridge Bay, the head of Minto Inl., Oterkvik Pt. and Ulukhaktok. These records extend the distribution of the taxon westward in Canada, and the subspecies is newly recorded for the Northwest Territories (see map in Kirschner 2002a: 166). All specimens from the eastern Canadian Arctic are considered to be this subspecies, recorded from Baffin and Southampton islands, a few sites on Ellesmere I., mainland Nunavut along western Hudson Bay and northern Quebec and Labrador (Aiken et al. 2007, Hay and Payette 2013).

NORTHWEST TERRITORIES. Minto Inl. (head): Edlund 164 (CAN), Porsild 17375 (CAN). Ulukhaktok: Edlund 778 (CAN). NUNAVUT. Cambridge Bay: Saarela & Teeter 5289 (CAN). Oterkvik Pt.: Gillespie et al. 7690 (CAN, O).

Juncus arcticus subsp. alaskanus Hultén (J. balticus var. alaskanus (Hultén) A.E.Porsild), Fig. 10B–Alaska rush | Asian (NE)–amphi-Beringian–North American (NW)

Recorded from Kuujjua R., the head of Minto Inl., “30-Mile Cr.”, Cambridge Bay, Clouston B. and Johansen B. This western subspecies is the common one on the island. Elsewhere in the Canadian Arctic Archipelago it is recorded from Banks I., and on the mainland it extends to Bathurst Inl. and southeastern mainland Nunavut (Porsild and Cody 1980, Kirschner 2002c, Cody et al. 2003, Aiken et al. 2007, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Kuujjua R.: Edlund 651 (CAN), Gillespie et al. 9911 (ALA, ari, CAN, O). Minto Inl. (head): Gillespie et al. 10150 (ALA, CAN, MT, O), 10229 (ALA, CAN, O). NUNAVUT. “30-Mile Cr.”: Bennett et al. 14-0343 (BABY, chars). Cambridge Bay: Edlund & Argus 12864 (CAN), Gillespie et al. 8502 (CAN, O), Stephens 1130 (CAN). Clouston B.: Gillespie et al. 7752 (ALA, CAN, MT, O). Johansen B.: Gillespie et al. 8111 (ALA, CAN, MT, O).

Juncus biglumis L., Figs 10C, 11A–Two-flowered bog rush | Circumpolar-alpine

Previously recorded from Cambridge Bay, the head of Minto Inl., Natkusiak P., Richard Collinson Inl., Storkerson P., Washburn L. (Porsild obs., conf.) and Ulukhaktok (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.), Hadley B. (conf.), Richardson I., Surrey L. and Wellington B. Newly recorded from Albert Edward B., Boot Inl., C. Wollaston, Clouston B., Collinson P., Colville Mts., Ferguson L., Greiner L., Kuujjua R., Mt. Pelly, Namaycush L., “Oldenburg L.”, Oterkvik Pt., an inland site on Prince Albert P., Read I., Sinclair Cr., Walker B. and northwestern Wollaston P. Many of these collections close the conspicuous large gap across most of Victoria I. in a previous distribution map (Aiken et al. 2007). Widespread throughout the Canadian Arctic Archipelago and known from numerous mainland sites (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Aiken et al. 2007, Hay and Payette 2013, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9559 (ALA, CAN, MT, O). C. Wollaston: Edlund 32 (CAN). Kuujjua R.: Gillespie et al. 9778 (ALA, CAN, O). Minto Inl. (head): Edlund 121, 162 (CAN), Gillespie et al. 9501 (ALA, ari, CAN, O), 10296 (CAN, O), 17374, 17376 (CAN). Natkusiak P.: Edlund 77 (CAN). “Oldenburg L.”: Oldenburg 45-1371 (CAN). Prince Albert P.: Oldenburg 54-673 (MIN). Richard Collinson Inl.: Edlund 700 (CAN). Ulukhaktok: Edlund 357, 462, 755, 800 (CAN), Oldenburg 45-1601 (CAN), Porsild 17262 (CAN), Saarela & Bull 1484, 1492 (CAN). Walker B.: Oldenburg 45-1439 (CAN). Wollaston P.: Oldenburg 54-494a (MIN). NUNAVUT. Albert Edward B.: Ponomarenko VI-253 (CAN). Cambridge Bay: Bennett et al. 13-0240 (CAN, od), Calder et al. 24173 (DAO), Polunin s.n. (CAN), Stephens 1002, 1158 (KANU, KSTC), 966 (KANU), 1108 (KSTC), 1037, 1148, 1206 (CAN, KANU, KSTC). Clouston B.: Gillespie et al. 7748 (CAN). Collinson P.: Edlund & Argus 12754 (CAN). Colville Mts.: Gillespie et al. 7761 (CAN). Ferguson L. [Tahiryuaq]: Hainault 2012 (DAO). Greiner L.: Ponomarenko VI-230, VI-341B (CAN). Hadley B.: Edlund 66, 144 (CAN). Johansen B.: Gillespie et al. 7951 (CAN, O). Ovayok TP: Bennett & Sullivan 13-0286 (chars). Namaycush L.: Edlund 126 (CAN). Oterkvik Pt.: Gillespie et al. 7689 (CAN), 7787 (ALA, CAN, O). Read I.: Oldenburg 43-1008 (CAN). Sinclair Cr.: Gillespie et al. 8238 (ALA, CAN, O). Storkerson P.: Edlund 178, 295 (CAN). Washburn L.: Edlund & Argus 12795 (CAN), Oldenburg 46-2217 (CAN).

Juncus leucochlamys V.J.Zinger ex V.I.Krecz. | (J. castaneus Sm. pro parte., J. castaneus subsp. leucochlamys (V.J.Zinger ex V.I.Krecz.) Hultén), Figs 10D, 11B–Chestnut rush | Asian (N/C)–amphi-Beringian–North America (N)–amphi-Atlantic (W)

Previously recorded from Cambridge Bay, C. Wollaston, the head of Minto Inl. and Ulukhaktok (Porsild 1955, 1957, 1964, Porsild and Cody 1980). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.), Hadley B., Richardson I., Surrey L. and Wellington B. Newly recorded from Kuujjua R., Murray Pt. and Walker B. Elsewhere in the Canadian Arctic recorded from Baffin, Devon, Ellesmere and Southampton islands and numerous mainland sites (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Cody and Reading 2005, Aiken et al. 2007, Hay and Payette 2013, Saarela et al. 2013, Saarela et al. 2017b). The populations on the northwest part of Victoria I. mark the species’ northwestern limit.

NORTHWEST TERRITORIES. C. Wollaston: Edlund 65 (CAN). Kuujjua R.: Gillespie et al. 9860 (CAN), 9901 (ari, CAN, O). Minto Inl. (head): Edlund 125 (CAN), Gillespie et al. 10227 (ALA, CAN, MT, O), Porsild 17377 (CAN). Ulukhaktok: Edlund 359, 505, 799 (CAN), Porsild 17263 (CAN). Walker B.: Oldenburg 45-1438 (CAN). NUNAVUT. Cambridge Bay: Edlund & Argus 12626 (CAN), Oldenburg 44-899 (CAN). Johansen B.: Gillespie et al. 8017 (ALA, CAN, MT, O). Murray Pt.: Gillespie et al. 8201 (CAN).

Juncus triglumis subsp. albescens (Lange) Hultén (J. albescens Lange, J. triglumis var. albescens Lange), Figs 10E, 11C–Northern white rush | Asian (N)–amphi-Beringian–North American (N)–amphi-Atlantic (W)

Figure 11. 

A Juncus biglumis habit, Minto Inlet, NT, 22 July 2010 B Juncus leucochlamys habit, Gillespie et al. 9901 C Juncus triglumis subsp. albescens habit, Gillespie et al. 9859 D Luzula nivalis inflorescence (left) and habit (right), Gillespie et al. 9667. Photos by J.M. Saarela.

Previously recorded from Cambridge Bay, C. Peel, C. Wollaston, Hadley B., the head of Minto Inl., Mt. Bumpus, Namaycush L., east of the head of Prince Albert S. and Ulukhaktok. Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.), Surrey L. and Wellington B. Newly recorded from Boot Inl., Kuujjua R., the Greiner L. watershed, Oterkvik Pt. and Sinclair Cr. Elsewhere in the Canadian Arctic recorded from Axel Heiberg, Baffin, Banks, Coats, Devon, Ellesmere, King William and Southampton islands and several mainland sites (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Cody and Reading 2005, Aiken et al. 2007, Hay and Payette 2013, Saarela et al. 2013, Saarela et al. 2017b). There is a conspicuous gap in distribution in the central Canadian Arctic Archipelago (Brooks and Clemants 2002, Aiken et al. 2007).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9555 (ALA, ari, CAN, MT, O, UBC). C. Wollaston: Edlund 32, 64 (CAN). Kuujjua R.: Edlund 652 (CAN), Gillespie et al. 9859 (CAN). Minto Inl. (head): Edlund 163 (CAN), Gillespie et al. 10032 (CAN, O), Porsild 17373 (CAN). Ulukhaktok: Bliss s.n. (ALTA), Edlund 358, 754, 800, 17261 (CAN), Oldenburg 42-69 (CAN). NUNAVUT. Cambridge Bay: Bennett et al. 13-0261 (chars, UBC), Gillespie et al. 8440 (CAN, O), Gould s.n. (ALA), Stephens 1035 (CAN, KANU, KSTC). C. Peel: Edlund 2 (CAN). Greiner L.: Ponomarenko VI-231 (CAN). Johansen B.: Gillespie et al. 8015 (CAN, O). Mt. Bumpus: Edlund 177 (CAN). Namaycush L.: Edlund 35 (CAN). Oterkvik Pt.: Gillespie et al. 7788 (CAN, O). Prince Albert S. (head): Edlund & Argus 12822 (CAN). Sinclair Cr.: Gillespie et al. 8336 (CAN).

Luzula DC. [3]

Key to Luzula [adapted from Swab (2000) and Kirschner (2002b)]

1 Inflorescences open, paniculate cymes, flowers solitary at the end of the capillary branches; seeds 1.2–1.6 mm L. wahlenbergii
Inflorescences spike-like with flowers in heads; seeds 0.8–1.2 mm 2
2 Basal leaves ± flat, usually up to 5 cm, (2–)3–4 mm wide, tip obtuse, often slightly swollen, with a spinuliform mucro; cauline leaves (1–)2, 1–2(–3) cm; bracteole apices sparsely ciliate L. nivalis
Basal leaves ± subcanaliculate to ± flat, up to 6–9 cm, 1.5–2.5 mm wide, tip acuminate; cauline leaves 1–2, usually 2–4 cm; bracteole apices fimbriate-ciliate L. confusa

Luzula confusa Lindeb., Fig. 10F–Northern woodrush | Circumpolar-alpine

Previously recorded from Cambridge Bay, Ferguson L. [Tahiryuaq], “Long L.”, the head of Minto Inl. and Ulukhaktok (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.), Richardson I. and Surrey L. Newly recorded from Greiner L. and Murray Pt. Observed in Ovayok TP by B.A.B. in 2013; a voucher is needed. Widespread throughout the Canadian Arctic (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Aiken et al. 2007, Hay and Payette 2013, Saarela et al. 2013, Saarela et al. 2017b). The distribution gap on the northeastern half of Victoria I. is likely an artefact of sampling, as the species is recorded from most adjacent islands to the north and east (Aiken et al. 2007).

NORTHWEST TERRITORIES. Minto Inlet (head): Porsild 17378 (CAN). Ulukhaktok: Edlund 811, 845 (CAN), Porsild 17264 (CAN). NUNAVUT. Cambridge Bay: Bennett et al. 13-0304 (ALA, BABY, CAN, chars, UBC), 14-0379 (UBC). Ferguson L. [Tahiryuaq]: Bennett et al. 14-0409 (UBC), Hainault 2074 (DAO). Greiner L.: Ponomarenko VI-279B, VI-282B (CAN). Johansen B.: Gillespie et al. 7847 (ALA, CAN, MT, O), 7903, 8028 (CAN, O). “Long L.”: Lambert s.n. (CAN). Murray Pt.: Gillespie et al. 8207 (ALA, CAN, MT, O), 8208 (ALA, BABY, CAN, MT, O, US), 8202 (CAN, O). Oterkvik Pt.: Gillespie et al. 7680 (ALA, CAN, MT, O), 7574 (ALA, CAN, O).

Luzula nivalis (Laest.) Spreng. (L. arctica Blytt), Figs 10G, 11D–Arctic wood rush | Circumpolar-alpine

Previously recorded from Anderson B., Collinson P., Greely Haven, Hadley B., the head of Minto Inl., Namaycush L., Natkusiak P., Shaler Mts., Storkerson P. and Ulukhaktok (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.), Richardson I. and Surrey L. Newly recorded from Albert Edward B., Boot Inl., Ferguson L., Greiner L., Kuujjua R., Mt. Pelly, Murray Pt., the north side of Prince Albert S., Sinclair Cr. and “Trunsky L.” Widespread throughout the Canadian Arctic islands and across the mainland (Porsild and Cody 1980, Korol 1992, Aiken et al. 2007, Hay and Payette 2013, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9667 (ALA, CAN, MT, O). Kuujjua R.: Gillespie et al. 9779 (ALA, ari, CAN, MT, O, UBC), 9979 (ALA, CAN, O). Minto Inl. (head): Edlund 161 (CAN), Gillespie et al. 10013 (ALA, ari, CAN, MT, O), 9505 (CAN). Natkusiak P.: Edlund 79 (CAN). Prince Albert S. (N): Oldenburg 46-2272 (CAN). Shaler Mts.: Edlund 542 (CAN). Ulukhaktok: Bliss s.n. (ALTA), Edlund 356, 477, 715 (CAN), Oldenburg 42-85, 45-1599 (CAN), Porsild 17265 (CAN), Saarela & Bull 1478 (CAN). NUNAVUT. Albert Edward B.: Ponomarenko VI-335A (CAN). Anderson B.: Edlund & Argus 12711 (CAN). Cambridge Bay: Oldenburg 44-927 (CAN), Polunin s.n. (CAN, 2 sheets), Stephens 1042 (CAN, KSTC). Collinson P.: Edlund & Argus 12765 (CAN). Ferguson L. [Tahiryuaq]: Hainault 2043 (DAO). Greely Haven: Fortier 93 (CAN). Greiner L.: Ponomarenko VI-274, VI-279C, VI-298, VI-298A (CAN). Hadley B.: Edlund 112, s.n. (CAN). Johansen B.: Gillespie et al. 8172 (ALA, ALTA, BABY, CAN, MT, O, UBC, US), 8027 (ALA, CAN, O). Ovayok TP: Gould s.n. (ALA). Murray Pt.: Gillespie et al. 8206 (ALA, CAN, O). Namaycush L.: Edlund & Roncato-Spencer 56 (CAN). Sinclair Cr.: Gillespie et al. 8230 (ALA, CAN, O). Storkerson P.: Edlund 176 (CAN). “Trunsky L.”: Bennett et al. 14-0392 (BABY, CAN).

Luzula wahlenbergii Rupr., Fig. 10H–Wahlenberg’s woodrush | Circumpolar-alpine

Known from a single collection we made in 2008 at Johansen B.; see Gillespie et al. (2015). Elsewhere in Nunavut recorded from southern Baffin I. and numerous mainland sites (Porsild and Cody 1980, Aiken et al. 2007).

NUNAVUT. Johansen B.: Gillespie et al. 8170 (CAN).

Cyperaceae [2/33/35]

Key to Cyperaceae [adapted from Ball et al. (2002)]

1 Flowers and achenes partially to completely enclosed in scalelike structure (perigynium); perigynium in axil of scale; flowers unisexual; perianth absent Carex
Flowers and achenes not enclosed in scalelike perigynium; flowers in axil of scale; flowers usually bisexual, sometimes some, rarely all, flowers unisexual; perianth persistent, of 10–25 smooth, hairlike bristles Eriophorum

Carex L. [26/27]

Key to Carex [adapted from Porsild and Cody (1980), Ball and Reznicek (2002), Ball (2002) and Toivonen (2002)]

1 Margins of perigynium open; terminal and distal spikelets usually 1-flowered, staminate; proximal spikelets 1-flowered and pistillate, or 2–4-flowered and bisexual with 1 pistillate flower proximally and 1–3 staminate flowers distally 2
Margins of perigynium fused; all spikelets 1-flowered 4
2 Inflorescences compound; basal leaf sheaths dull, base of blade usually persistent C. simpliciuscula subsp. subholarctica
Inflorescences simple; basal leaf sheaths somewhat glossy, bladeless 3
3 Perigynia 2–3.5 mm, margins free to base; scales ovate, 2–3.5 mm; midvein distinct almost to tip; anthers 1–1.5 mm; achenes 2–2.8 mm C. myosuroides
Perigynia 3.5–5.5 mm, margins connate near base; scales obovate-circular, 3.5–5 mm; midvein distinct only near base; anthers 2–3 mm; achenes 2.6–4 mm C. borealipolaris
4 Spikes solitary 5
Spikes compound 9
5 Pistillate scales early deciduous; perigynia deflexed at maturity C. microglochin
Pistillate scales persistent; perigynia not deflexed at maturity 6
6 Stigmas 2; plants densely cespitose 7
Stigmas 3; plants cespitose or loosely cespitose 8
7 Spike gynaecandrous (staminate flowers proximal, pistillate flowers distal); perigynia 1.5–2 mm; plants of seashores C. ursina
Spike androgynous (pistillate flowers proximal, staminate flowers distal); perigynia 3–5 mm; plants of dry, exposed tundra C. nardina
8 Plants dioecious, rarely monoecious; rhizomes short, sometimes inconspicuous; perigynia hairy C. scirpoidea subsp. scirpoidea
Plants monoecious, spike androgynous; rhizomes long; perigynia glabrous C. rupestris
9 Spikes all bisexual and sessile 10
Spikes mostly unisexual, the terminal one staminate or bisexual 13
10 Some or all spikes androgynous 11
Some or all spikes gynaecandrous 12
11 Plants rhizomatous, stolons lacking; perigynium beak 0.5–1 mm C. maritima
Plants rhizomatous and long-stoloniferous (vegetative stems ascending to erect when young, becoming prostrate stolons at maturity); perigynium beak 0.3–0.6 mm C. chordorrhiza
12 Plants loosely cespitose; culms erect, 10–15(–30) cm; spikes 2–3(–4); lateral spikes gynecandrous, containing 3–8 perigynia, oblong-clavate; perigynia elliptic, green-white proximally, pale brown distally, often brown in age; beak indistinct C. marina
Plant densely cespitose; culms often arching, weak, 10–25 cm; spikes 2–4; lateral spikes pistillate, containing 5–10(–15) perigynia, oblong-linear; perigynia broadly elliptic-obovate to lanceolate, light to pale brown, often gray-brown at maturity; beak short C. glareosa
13 Stigmas 2 14
Stigmas 3 19
14 Terminal spike gynecandrous C. bicolor
Terminal spike staminate 15
15 Perigynia somewhat glossy, glabrous, more or less inflated, beak distinct; lateral spikes usually pendant C. saxatilis
Perigynia dull, usually papillose, sometimes glabrous, not inflated, beak indistinct; lateral spikes erect 16
16 Pistillate scales with a prominent, scabrous awn on at least the proximal scales; leaf blades involute, 1–2 mm wide C. subspathacea
Pistillate scales with apex acute, acuminate, or mucronate, lacking a prominent, scabrous awn; leaf blades not involute, the widest > 2 mm wide 17
17 Proximal bract longer than inflorescence (usually at least 1.5× as long) C. aquatilis subsp. stans
Proximal bract shorter than or equal to inflorescence (C. bigelowii) 18
18 Perigynia green, spotted purple-black on apical 1/2, minutely papillose; stipe 0.15–0.45 mm; proximal pistillate spike loosely flowered, base often attenuate, less often cuneate C. bigelowii subsp. bigelowii
Perigynia green, often white at maturity, uniformly purple-brown on apical 1/2, strongly or minutely papillose; stipe 0–0.15 mm; proximal pistillate spike densely flowered, base cuneate, less often attenuate C. bigelowii subsp. lugens
19 Terminal spike gynaecandrous 20
Terminal spike staminate 21
20 Perigynia lanceolate, 3.3–5.5 mm, margins ciliate; pistillate scales ovate, 2.8–4.2 mm; staminate scales oblong-obovate or obovate, 3–5 mm; achenes 1.5–2 × 0.9–1 mm C. fuliginosa subsp. misandra
Perigynia lanceolate to ovate-lanceolate, 1.5–3.3 mm, margins entire or serrulate; pistillate scales obovate or obovate-circular, 1.6–2.1 mm; staminate scales oblong-ovate 2–2.8 mm; achenes 1.1–1.4 × 0.6–0.9 mm C. krausei
21 Inflorescence capitate, the lateral spikes short-peduncled C. glacialis
Inflorescence not capitate 22
22 Pistillate spikes sessile or nearly sessile C. membranacea
Pistillate spikes on peduncles as long or longer than the spikes 23
23 Plants tufted 24
Plants rhizomatous 25
24 Pistillate scales black with pale midvein, ovate or oblong-ovate, 3–4.8 × 0.9–1.6 mm; lateral spikes 4–7 mm wide; terminal spike 6–15 × 2–5 mm, usually over-topping lateral spikes, sometimes overlapping some of them C. atrofusca
Pistillate scales medium to dark brown with pale midvein, ovate, obovate or obovate-circular, 2.3–3.5 × 0.8–1.2 mm; lateral spikes 3–4 mm wide; terminal spike 4–10 × 0.7–1.4 mm, level with or over-topped by some of the lateral spikes C. capillaris subsp. fuscidula
25 Lateral spikes ± erect; proximal perigynia loosely arranged; perigynium beak distinct, (0.4–)0.6–1.8(–2.2) mm C. vaginata
Lateral spikes drooping, at least the lowermost ones; proximal perigynia densely arranged; perigynium beak absent or indistinct, to 0.5 mm 26
26 Perigynia pale green; proximal bracts of inflorescence 0.5–2 cm; spikes 2–4 C. rariflora
Perigynia pale yellow proximally, brown or black distally; proximal bracts of inflorescences 0.5–14 cm; spikes 3–8 C. petricosa subsp. petricosa

Carex aquatilis subsp. stans (Drejer) Hultén (C. aquatilis var. minor Boott, C. stans Drejer), Figs 12A, 13A–Arctic water sedge | Circumpolar-alpine

Figure 12. 

Species distribution maps. Cyperaceae: A Carex aquatilis subsp. stans B Carex atrofusca C Carex bicolor D Carex bigelowii subsp. bigelowii E Carex bigelowii subsp. lugens F Carex borealipolaris G Carex capillaris subsp. fuscidula H Carex chordorrhiza I Carex fuliginosa subsp. misandra J Carex glacialis K Carex glareosa subsp. glareosa L Carex krausei.

Figure 13. 

A Carex aquatilis subsp. stans habit, 18 July 2010 B Carex atrofusca habit, head of Minto Inlet, 25 July 2010 C Carex borealipolaris inflorescence, Gillespie et al. 9900 D Carex borealipolaris habit, Gillespie et al. 9900 E Carex fuliginosa subsp. misandra habit, Kuujjua River, NT, 18 July 2010. Photos by J.M. Saarela.

Previously recorded from Cambridge Bay, C. Wollaston, Hadley B., Kuujjua R., Mt. Bumpus, Namaycush L., Natkusiak P., north and southeast of the head of Prince Albert S., Richard Collinson Inl., Storkerson P., Tahiryuaq and Ulukhaktok (Porsild 1955, 1957, 1964, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.), Richardson I., Surrey L. and Wellington B. Newly recorded from Albert Edward B., Greiner L., Oterkvik Pt., Murray Pt., an inland site on Prince Albert P., Read I., Sinclair Cr., Walker B. and Wollaston P. Widespread throughout the Canadian Arctic islands and on the mainland (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Aiken et al. 2007, Saarela et al. 2013).

NORTHWEST TERRITORIES. Boot Inl.: Dutilly 18706 (US), Gillespie et al. 9562 (ALA, CAN, O). C. Wollaston: Edlund 42 (CAN), 163 (CAN). Kuujjua R.: Edlund 634 (CAN), Gillespie et al. 9783 (ALA, CAN, MT, WIN), 9945 (ALA, ari, CAN, O, WIN), 9905 (ALA, CAN, MT, O). Minto Inl. (head): Edlund 135, 148, 171 (CAN), Gillespie et al. 9492 (CAN, O), 10144 (ALA, CAN, O), Porsild 17820 (CAN). Prince Albert P.: Oldenburg 54-656 (MIN). Richard Collinson Inl.: Edlund 132, 689 (CAN). Tahiryuaq: Edlund 390 (CAN). Ulukhaktok: Bandringa 344 (CAN, UBC), Dutilly 16847 (US), Edlund 360, 492, 828, 907 (CAN), Oldenburg 45-1578 (CAN), Porsild 17256 (CAN), Svoboda 745029 (TRTE, UBC). Walker B.: Oldenburg 45-1432, 45-1436 (CAN). Wollaston Pen.: Oldenburg 54-497 (MIN, UBC). NUNAVUT. Albert Edward B.: Ponomarenko VI-252, VI-267 (CAN). Cambridge Bay: Bennett et al. 14-0366 (MICH, UBC), 13-0183 (chars, DAO), Calder et al. 24189 (DAO), Consaul & Gillespie 1108 (CAN), Edlund & Argus 12618 (CAN, TRTE), Fortier 17 (CAN), Gillespie et al. 8404 (ALA, BABY, CAN, MT, O), Oldenburg 44-964 (CAN), Polunin s.n. (CAN, 2 sheets), Ponomarenko VI-086A, VI-087 (CAN), Porsild 17463 (CAN), Smith & Sweatman 34A (DAO), Stephens 965 (ID, KANU), 956, 1024, 1198 (KANU), 1126 (KANU, KSTC), 958, 1127, 1197 (CAN, KANU), 1058 (CAN). Ferguson L. [Tahiryuaq]: Bennett et al. 14-0417 (BABY, DAO, MICH), Hainault 1929 (DAO), Jones & Hainault 1866 (DAO). Greiner L.: Ponomarenko VI-124C, VI-136, VI-149, VI-158, VI-190, VI-203C, VI-240, VI-329c (CAN). Hadley B.: Edlund 35, 104, 425 (CAN). Johansen B.: Gillespie et al. 7916 (ALA, CAN, MT, O), 7906 (CAN, O). Mt. Bumpus: Edlund 203, 216, 248 (CAN). Murray Pt.: Gillespie et al. 8190 (ALA, BABY, CAN, MT, O). Namaycush L.: Edlund 34, 76, 137, 138 (CAN). Oterkvik Pt.: Gillespie et al. 7479 (ALA, CAN, O), 7545 (CAN, O). Prince Albert S. (head): Edlund 100, 24, 93 (CAN). Read I.: Oldenburg 43-1007b (CAN). Sinclair Cr.: Gillespie et al. 8299 (ALA, ALTA, BABY, CAN, MT, O, UBC, US). Storkerson P.: Edlund 183, 281 (CAN). Tahoe L.: Porsild 17450 (CAN). Tuktu R.: Gould s.n. (ALA). Washburn L.: Edlund & Argus 12799 (CAN, TRTE).

Care x atrofusca Schkuhr, Figs 12B, 13B–Dark brown sedge | Circumpolar–alpine

Previously recorded from Cambridge Bay, Ferguson L., Jonnessee L., the head of Minto Inl., Mt. Pelly, Tahiryuaq and Ulukhaktok (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.), Richardson I., Surrey L., Wellington B. and Mt. Pelly (conf.). Newly recorded from Albert Edward B., Boot Inl., Falaise B., Hadley B., Kuujjua R., Mt. Bumpus, Oterkvik Pt., Read I. and Sinclair Cr. Elsewhere in the Canadian Arctic recorded from Baffin, Banks, Coats, Ellesmere, Devon and Southampton islands and across the mainland (Porsild and Cody 1980, Korol 1992, Aiken et al. 2007, Saarela et al. 2013).

NORTHWEST TERRITORIES. Boot Inl.: Dutilly 18705a (US), Gillespie et al. 9641 (ALA, CAN, MT, WIN). Minto Inl. (head): Gillespie et al. 9487 (CAN, O), Porsild 17364 (CAN). Kuujjua R.: Gillespie et al. 9775 (ALA, ari, CAN, MT, O, UBC). Richard Collinson Inl.: Edlund 684 (CAN). Tahiryuaq: Edlund 405 (CAN). Ulukhaktok: Edlund 312, 490 (CAN, ID), 725 (CAN), Porsild 17247 (CAN). NUNAVUT. Albert Edward B.: Ponomarenko VI-254A, VI-266 (CAN). Cambridge Bay: Bennett et al. 13-0169 (BABY, chars, od, UBC), Calder et al. 24156 (DAO), Edlund & Argus 12670 (CAN, TRTE), Gillespie et al. 8409 (ALA, BABY, CAN, MT, O), Gould s.n. (ALA), Polunin s.n. (CAN, 2 sheets), Ponomarenko VI-080C, VI-085, VI-089A (CAN), Porsild 21600 (CAN), Stephens 1039 (KANU, KSTC), 968 (CAN, KANU), 1057, 1128 (CAN, KANU, KSTC). Falaise B.: Eriksen et al. 951 (ALA). Ferguson L. [Tahiryuaq]: Hainault 2057 (DAO), Hainault & Jones 1869 (DAO). Greiner L.: Ponomarenko VI-100C, VI-100D, VI-100E, VI-130, VI-135a, VI-154A (CAN). Hadley B.: Edlund 146 (CAN). Jonnessee L.: Edlund & Argus 12779, 12780 (mixed with C. saxatilis), 12782 (CAN). Johansen B.: Gillespie et al. 7947 (ALA, BABY, CAN, MT, O). Mt. Bumpus: Edlund 161, 225 (CAN). Ovayok TP: Gould s.n. (ALA). Oterkvik Pt.: Gillespie et al. 7478 (ALA, CAN, MT, O), Gillespie et al. 7612 (ALA, CAN, O). Read I.: Ross 10 (ALTA). Sinclair Cr.: Gillespie et al. 8305 (ALA, BABY, CAN, MT, O, US).

Carex bicolor Bellardi ex All., Fig. 12C–Bicoloured sedge | Circumpolar–alpine

Newly reported from Victoria I. and the western Canadian Arctic Archipelago based on a collection we made in 2008 in the Johansen B. area; see Gillespie et al. (2015). Two additional records from Victoria I. are newly reported here: one from Cambridge Bay collected in 2013 along the road to Ovayok (Mount Pelly), where it was growing in a Carex aquatilis fen surrounded by Dryas integrifolia/Salix arctica tundra with Salix richardsonii, Saxifraga hirculus and Carex simpliciuscula, and one from the Kuujjua R. area, collected in 1982. The latter specimen had been misidentified as Carex rariflora. Elsewhere in the Canadian Arctic recorded from southern Baffin, Coats and Nottingham islands and a few sites on mainland Nunavut and Northwest Territories (Porsild 1943, Porsild and Cody 1980, Cody et al. 1989, Gould and Walker 1997, Aiken et al. 2007, Saarela et al. 2013, Gillespie et al. 2015, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Kuujjua R.: Edlund 646 (CAN). NUNAVUT. Cambridge Bay: Bennett et al. 13-0199 (BABY, CAN). Johansen B.: Gillespie et al. 8118 (CAN).

Carex bigelowii Torr. ex Schwein. subsp. bigelowii, Fig. 12D–Bigelow’s sedge | North American–amphi-Atlantic

Newly recorded for Victoria Island, known from Cambridge Bay, Ferguson L., Johansen B. and Oterkvik Pt. The Ferguson L. records were not previously determined to subspecies. This is a primarily eastern Arctic taxon recorded elsewhere in the Canadian Arctic from numerous mainland sites as well as Baffin, Devon, Ellesmere and Southampton islands (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Aiken et al. 2007). It reaches its known western limit in the Canadian Arctic Archipelago in the study area and on the mainland along the Coppermine R. (Saarela et al. 2017b). Thannheiser et al. (2001) recorded C. bigelowii from six sites and C. lugens from one (Richardson I.). We find the former taxon to be rare on Victoria I. and the latter to be common. It is possible that the taxon concepts in that paper were inadvertently mixed up.

NUNAVUT. Cambridge Bay: Polunin s.n. (CAN). Ferguson L. [Tahiryuaq]: Hainault 2077, 2134 (DAO). Johansen B.: Gillespie et al. 7876 (ALA, CAN, O). Oterkvik Pt.: Gillespie et al. 7799 (ALA, CAN, MT, O).

Carex bigelowii subsp. lugens (Holm) T.V.Egorova (C. consimilis Holm, C. lugens Holm), Fig. 12E–Spruce muskeg sedge | Eurasian–amphi-Beringian

Previously known from Ulukhaktok and the head of Prince Albert S. (Porsild 1955, 1957, 1964, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Richardson I. Newly recorded from Cambridge Bay, the head of Minto Inl., Johansen B., Mt. Lady Pelly, “Oldenburg L.”, Oterkvik Pt., Read I., Sinclair Cr., Surrey L., Walker B. and Washburn L. Elsewhere in the Canadian Arctic recorded from Banks I. and some mainland sites, reaching its known eastern limit on central mainland Nunavut (Porsild and Cody 1980, Aiken et al. 2007, Saarela et al. 2013, Saarela et al. 2017b). This subspecies, a western Arctic taxon, is more common than subsp. bigelowii on Victoria I.

NORTHWEST TERRITORIES. Minto Inl. (head): Gillespie et al. 10269 (ALA, ari, CAN, O, UBC, WIN), 10270 (CAN, O), 10282 (CAN, WIN). “Oldenburg L.”: Oldenburg 45-1373 (CAN). Prince Albert S.: Porsild 17436 (CAN). Ulukhaktok: Edlund 910 (CAN), Oldenburg 42-83, 42-86, 45-1561 (CAN). Porsild 17248 (CAN), Saarela & Bull 1474 (ALA, CAN, MT, O). Walker B.: Oldenburg 45-1415 (CAN). NUNAVUT. Cambridge Bay: Oldenburg 44-905A, 44-961 (CAN), Saarela & Teeter 5284 (CAN). Johansen B.: Gillespie et al. 7952 (ALA, BABY, CAN, MT, O), 8049 (ALA, BABY, CAN, MT, O, US), 7845 (ALA, CAN, O). Mt. Lady Pelly [Amaaqtuq]: Jones & Hainault 34a (DAO). Oterkvik Pt.: Gillespie et al. 7557 (ALA, CAN, MT, O), 7784 (ALA, CAN, MT, O), 7607 (CAN, O). Read I.: Oldenburg 42-494, 43-1005, 43-893, 43-971 (CAN). Sinclair Cr.: Gillespie et al. 8308 (ALA, ALTA, BABY, CAN, MT, O, UBC, US), 8244 (CAN). Surrey L.: Edlund & Argus 12805 (CAN). Washburn L.: Oldenburg 46-2219 (CAN).

Carex borealipolaris S.R.Zhang (Kobresia sibirica (Turcz. ex Ledeb.) Boeckeler, K. hyperborea A.E.Porsild), Figs 12F, 13C, D–Siberian bog sedge | Asian (N/C)–amphi-Beringian

Previously recorded from Cambridge Bay, Namaycush L., Ulukhaktok and Walker B. (Porsild 1955, 1957, 1964, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from the head of Minto Inl. (conf.), Richardson I., Johansen B. (conf.), Hadley B. and Mt. Pelly. Newly recorded from Boot Inl., Greiner L., Kuujjua R., Murray Pt., Oterkvik Pt., Read I., Sinclair Cr. and Washburn L. Elsewhere in the Canadian Arctic recorded from scattered sites on mainland Nunavut and Northwest Territories (Porsild and Cody 1980, Aiken et al. 2007, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9557 (ALA, CAN, O, WIN). Kuujjua R.: Gillespie et al. 9729 (ALA, ari, CAN, MT, O), 9782 (ALA, CAN, MT, O), 9900 (ALA, ari, CAN, MT, O, UBC, US, WIN). Minto Inl. (head): Gillespie et al. 10284 (CAN, O), 10297 (ALA, CAN, O, WIN). Ulukhaktok: Edlund 859 (CAN), Porsild 17260 (ALTA, CAN), Saarela & Bull 1495 (ALA, CAN, O). Walker B.: Porsild 17487 (CAN). NUNAVUT. Cambridge Bay: Bennett et al. 13-0188 (BABY, chars, od), 13-0611 (CAN), Consaul & Gillespie 1127 (CAN), Dutilly & Duman 37110 (US), Edlund & Argus 12688 (CAN), Gillespie et al. 8371 (ALA, BABY, CAN, MT, O), Oldenburg 44-920 (CAN), Polunin s.n. (CAN, 2 sheets), Ponomarenko VI-086B, VI-090A (CAN), Porsild 21608 (CAN). Ferguson L. [Tahiryuaq]: Hainault 2135 (DAO), Jones & Hainault 1863A (DAO). Greiner L.: Ponomarenko VI-302 (CAN). Johansen B.: Gillespie et al. 7950 (ALA, BABY, CAN, MT, O, UBC, US), 7840 (CAN, O). Murray Pt.: Gillespie et al. 8205 (CAN, O). Namaycush L.: Edlund & Roncato-Spencer 109 (CAN). Oterkvik Pt.: Gillespie et al. 7556 (ALA, BABY, CAN, MT, O, US, WIN). Read I.: Oldenburg 43-986 (CAN). Sinclair Cr.: Gillespie et al. 8229 (ALA, CAN, O). Washburn L.: Oldenburg 46-2221 (CAN).

Carex capillaris subsp. fuscidula (V.I.Krecz. ex T.V.Egorova) Á.Löve & D.Löve, Fig. 12G–Hair sedge | Circumpolar-alpine

Previously recorded from Cambridge Bay, Read I., Tahoe L. (Porsild obs.), Ulukhaktok (Porsild obs., conf.) and Walker B. (Porsild obs.) (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) recorded C. capillaris subsp. capillaris (probably including both subsp. fuscidula and C. krausei) from Johansen B. (conf.) and the head of Minto Inl. (conf.). Newly recorded from Boot Inl., Kuujjua R., Mt. Bumpus, Oterkvik Pt. and Sinclair Cr. Elsewhere in the Canadian Arctic recorded from Axel Heiberg, Baffin, Banks, Ellesmere, Somerset and Southampton islands, scattered sites on mainland Nunavut and Northwest Territories, and northern Quebec and Labrador (Porsild and Cody 1980, Aiken et al. 2007, Saarela et al. 2013, Sokoloff 2015, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9675 (CAN). Kuujjua R.: Gillespie et al. 9774 (CAN, MT, O), 9946 (ALA, CAN, MT, WIN). Minto Inl. (head): Gillespie et al. 10240 (ALA, CAN, MT, O), 10281 (CAN, O). Ulukhaktok: Edlund 313, 772, 815, 896 (CAN). NUNAVUT. Cambridge Bay: Bennett et al. 13-0184 (BABY, chars), Polunin s.n. (CAN), Stephens 1191 (CAN). Johansen B.: Gillespie et al. 7844 (CAN), 7987 (CAN). Mt. Bumpus: Edlund 284 (CAN). Oterkvik Pt.: Gillespie et al. 7571 (ALA, CAN, O), 7685 (CAN, O). Sinclair Cr.: Gillespie et al. 8306a (CAN). Read I.: Oldenburg 43-888, 43-995 (CAN), Porsild 17187 (CAN).

Carex chordorrhiza L.f., Fig. 12H–Creeping sedge | Circumboreal-polar

Previously recorded from Tahoe L., where collected in 1949, and a lake edge 1.6 km northeast of Cambridge Bay (Porsild 1955, 1957, 1964, Aiken et al. 2007). Newly recorded from Greiner L. and the vicinity of a pingo on Wollaston P. Targeted efforts were made by B.A. Bennett to rediscover this species near Cambridge Bay during 2013 and 2014 fieldwork, but it was not found. Elsewhere in the Canadian Arctic recorded from southern Baffin I. and mainland sites (Porsild and Cody 1980, Cody et al. 1989, Aiken et al. 2007, Saarela et al. 2013, Bennett 2015, Saarela et al. 2017b). The Victoria I. populations mark the northern edge of the species’ range.

NORTHWEST TERRITORIES. Wollaston P.: Oldenburg 54-504A (MIN). NUNAVUT. Cambridge Bay: Stephens 1279 (CAN). Greiner L.: Ponomarenko VI-122, VI-178A (CAN). Tahoe L.: Porsild 17449 (CAN).

Carex fuliginosa subsp. misandra (R.Br.) Nyman (C. misandra R.Br.), Figs 12I, 13E–Short leaf sedge | Circumpolar-alpine

Previously recorded from Anderson B., Byron B., Cambridge Bay, the head of Minto Inl., Natkusiak P., Namaycush L., N of a large lake in the Ekalluk River system about 90 km NNE of Cambridge Bay, Mt. Bumpus, Storkerson P., Tahiryuaq, Ulukhaktok and Walker B. (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it at Johansen B. (conf.), Mt. Pelly. (conf.), Richardson I., Surrey L. and Wellington B. Newly recorded from “30-Mile Cr.”, Albert Edward B., Boot Inl., Ferguson L., Greiner L., Kuujjua R., “Oldenburg L.”, Oterkvik Pt., the north side and inland from the head of Prince Albert S., Read I., Richard Collinson Inl., Sinclair Cr., Washburn L. and a site 90 km NNE of Cambridge Bay. Widespread throughout the Canadian Arctic (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Aiken et al. 2007, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9668 (ari, CAN, MT, O), 9669 (CAN), 9676 (CAN, O). Kuujjua R.: Gillespie et al. 9726 (CAN, O). Minto Inl. (head): Edlund 91 (CAN), Gillespie et al. 9488 (ALA, CAN, MT, O). Natkusiak P.: Edlund 78 (CAN). “Oldenburg L.”: Oldenburg 45-1372 (CAN). Prince Albert P.: Oldenburg 54-239, 54-663 (UBC). Prince Albert S. (head): Weerstra 32, 33 (DAO). Prince Albert S. (N): Oldenburg 46-2274 (CAN). Richard Collinson Inl.: Edlund 685 (CAN). Tahiryuaq: Edlund 405 (CAN). Ulukhaktok: Bliss s.n. (ALTA), Edlund 487 (CAN, ID), 728 (CAN), Oldenburg 42-84, 45-1570, 45-1574 (CAN), Porsild 17251, 17252 (CAN), Saarela & Bull 1494 (ALA, CAN, MT, O, WIN). Walker B.: Oldenburg 45-1417, 45-1419, 45-1422 (CAN), Porsild 17483, 17484 (CAN). NUNAVUT. “30-Mile Cr.”: Bennett et al. 14-0354 (UBC, CAN). Albert Edward B.: Ponomarenko VI-255 (CAN). Anderson B.: Edlund & Argus 12718 (CAN). Byron B.: Dushenko 8 (UVIC). Cambridge Bay: Bennett et al. 14-0321 (UBC), 13-0185 (BABY, chars, od), Calder et al. 24167, 24168 (DAO), Gillespie et al. 8365 (ALA, BABY, CAN, MT, O, UBC, US), Oldenburg 44-911, 44-913, 44-966 (CAN), Polunin s.n. (CAN, 2 sheets), Ponomarenko VI-080D, VI-086E, VI-095 (CAN), Porsild 21602 (DAO), Stephens 1185 (KANU, KSTC), 997 (KSTC), 1043, 1044 (CAN, KANU, KSTC), 1188 (CAN, KANU), Thomson s.n. (WIS), Washburn 4, 6, 27 (CAN). Ekalluk R.: Edlund & Argus 12741 (CAN). Eastern Victoria I.: Lee & Kittle s.n. (CAN). Ferguson L. [Tahiryuaq]: Bennett et al. 14-0416 (CAN, DAO, chars, od). Greiner L.: Ponomarenko VI-035A, VI-101b, VI-121, VI-131A, VI-151, VI-177, VI-238B (CAN). Hadley B.: Edlund 103, s.n. (CAN). Johansen B.: Gillespie et al. 7943 (ALA, BABY, CAN, MT, O, US), 8018 (ALA, BABY, CAN, MT, O), 8171 (ALA, CAN, O). Mt. Bumpus: Edlund 224, 253 (CAN). Ovayok TP: Bennett & Sullivan 13-0288 (BABY, chars), Gillespie et al. 8425 (CAN, O), Stephens 1045 (KANU), 1129 (ID, KANU). Namaycush L.: Edlund 133 (CAN), Edlund & Roncato-Spencer 105 (CAN). Natkusiak P.: Edlund 311 (CAN). Oterkvik Pt.: Gillespie et al. 7606 (ALA, CAN, O), 7643 (ALA, CAN, O). Prince Albert S.: Weerstra 27 (DAO). Read I.: Oldenburg 43-1011, 43-943 (CAN). Sinclair Cr.: Gillespie et al. 8306b (CAN, O). Storkerson P.: Edlund 187 (CAN). Washburn L.: Oldenburg 46-2227 (CAN).

Carex glacialis Mack., Fig. 12J–Glacier sedge | Circumpolar–alpine

Previously known from near the head of Prince Albert S. (mapped erroneously in Aiken et al. (2007) on north-central Victoria I.) and Ulukhaktok (Porsild obs.) (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Newly recorded from Kuujjua R., Colville Mts. and Oterkvik Pt. At one site in the Kuujjua R. area, the species was common in dry, almost bare soil among bedrock-dominated tundra growing with Deschampsia brevifolia, Dryas integrifolia and Salix arctica, in an area dominated by sand dunes. Elsewhere in the Canadian Arctic recorded from Axel Heiberg, Baffin, Coats, Ellesmere and Nottingham islands, and numerous mainland sites (Porsild 1964, Porsild and Cody 1980, Aiken et al. 2007, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Kuujjua R.: Gillespie et al. 9909 (ALA, CAN, WIN), 9978 (CAN, O). Prince Albert S.: Porsild 17365 (CAN). NUNAVUT. Colville Mts.: Gillespie et al. 7763 (CAN). Oterkvik Pt.: Gillespie et al. 7608 (ALA, BABY, CAN, MT, O), 7675 (ALA, CAN, O).

Carex glareosa Wahlenb. subsp. glareosa (C. glareosa var. amphigena Fernald), Fig. 12K–Gravel sedge | Circumpolar

Previously recorded from Ulukhaktok (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.). Newly recorded from Cambridge Bay (a collection previously determined by Porsild as C. amblyorhyncha (=C. marina)), where gathered in 1949 near the Hudson’s Bay Post and not recorded in the area since, and Oterkvik Pt. Elsewhere in the Canadian Arctic known from Baffin, Coats, Devon, Ellesmere and Southampton (CAN 583988) islands and mainland sites (Porsild and Cody 1980, Cody et al. 1984a, Cody et al. 1989, Korol 1992, Aiken et al. 2007, Saarela et al. 2013, Saarela et al. 2017b). This is a seashore species that, when present, is generally conspicuous.

NORTHWEST TERRITORIES. Ulukhaktok: Porsild 17249 (ALTA, CAN). NUNAVUT. Cambridge Bay: Porsild 17464 (CAN). Johansen B.: Gillespie et al. 8020 (ALA, CAN, O). Oterkvik Pt.: Gillespie et al. 7683 (CAN, O).

Carex krausei Boeckeler (C. capillaris subsp. robustior (Lange) Böcher), Figs 12L, 14A, B–Krause’s sedge | Circumpolar–alpine

Previously recorded from Ulukhaktok and the south side of Prince Albert S. (Aiken et al. 2007). Some of the reports of C. capillaris subsp. capillaris by Thannheiser et al. (2001) may be this species; vouchers require confirmation. Newly recorded from “30-Mile Cr.”, Boot Inl., Clouston B., Kuujjua R., the head of Minto Inl., Johansen B. and Oterkvik Pt. Elsewhere in the Canadian Arctic recorded from Axel Heiberg, Baffin, Banks, Coats, Ellesmere and Southampton islands and mainland sites (Porsild and Cody 1980, Gould and Walker 1997, Aiken et al. 2007, Saarela et al. 2013, Saarela et al. 2017b). The Working Group on General Status of NWT Species (2016) recorded the status of this species in Northwest Territories as “Undetermined”. The eight populations from the Northwest Territories portion of Victoria I. reported here, seven reported from Tuktut Nogait National Park and vicinity (Saarela et al. 2013) and at least nine other records of this species in the National Herbarium of Canada from mainland Northwest Territories, which have been revised (by J.M. Saarela) following current taxonomy, should be sufficient evidence to revise the status to Secure in the next version.

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9541 (ALA, ari, CAN, MT, O, UBC), 9675 (CAN). Kuujjua R.: Edlund 647 (CAN), Gillespie et al. 9977 (ALA, CAN, MT, O). Minto Inl. (head): Edlund 623 (CAN), Gillespie et al. 10157 (ALA, CAN, MT, O), 10230 (ALA, ari, CAN, MT, O, UBC, US, WIN). Prince Albert S. (S): Edlund 534 (CAN). NUNAVUT. “30-Mile Cr.”: Bennett et al. 14-0653 (BABY). Clouston B.: Gillespie et al. 7747 (CAN, O). Johansen B.: Gillespie et al. 7995 (ALA, BABY, CAN, MT, O, UBC), 8114 (ALA, ALTA, BABY, CAN, MT, O, UBC, US), 7843 (CAN, O). Oterkvik Pt.: Gillespie et al. 7686 (, O), 7710 (CAN).

Carex marina Dewey (C. amblyorhyncha V.I.Krecz.), Figs 15A, 14C, D – Sea sedge | Circumpolar-alpine

Figure 14. 

A Carex krausei habit, Gillespie et al. 9977 B Carex krausei inflorescence, Gillespie et al. 8114 C Carex marina habit D Carex marina habitat E Carex maritima habit, Johansen Bay, NU, 18 July 2008 F Carex membranacea inflorescence. Photos A, F by J.M. Saarela C, D by B.A. Bennett and B, E by R.D. Bull.

Figure 15. 

Species distribution maps. Cyperaceae: A Carex marina B Carex maritima C Carex membranacea D Carex microglochin E Carex myosuroides F Carex nardina G Carex petricosa subsp. petricosa H Carex rariflora I Carex rupestris J Carex saxatilis K Carex scirpoidea subsp. scirpoidea L Carex simpliciuscula subsp. subholarctica.

Previously recorded from Cambridge Bay, the head of Minto Inl. and Ulukhaktok (Porsild obs., conf.) (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.) and Richardson I. The specimen cited from Cambridge Bay (Porsild 17466) (Porsild 1955) apparently does not exist; another specimen with the same collection number at CAN is Carex scirpoidea, also cited by Porsild (1955). Whatever the reason for the error, more recent collections confirm the presence of the species in the Cambridge Bay area, though it was not mapped from there by Aiken et al. (2007). Newly recorded from Boot Inl., Ferguson L., Greiner L., Kuujjua R. and Sinclair Cr. Elsewhere in the Canadian Arctic recorded from Axel Heiberg, Baffin, Banks, Ellesmere, Nottingham and Southampton islands, as well as mainland sites (Porsild and Cody 1980, Aiken et al. 2007, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9640 (ALA, ari, CAN, MT, O). Kuujjua R.: Gillespie et al. 9776 (ALA, CAN, O). Minto Inl. (head): Gillespie et al. 9504 (ALA, CAN, MT, O), 10039 (ALA, ari, CAN, MT, O, UBC, US, WIN), 9491 (CAN, O, WIN), 10295 (ALA, CAN, O), Porsild 17366 (CAN). Ulukhaktok: Edlund 489, 518 (CAN), Oldenburg 42-102, 42-68, 42-99C (CAN). NUNAVUT. Cambridge Bay: Bennett et al. 13-0204 (BABY, chars, MICH, od, UAC), 14-0367 (CAN, MICH), 13-0565 (MICH), Gillespie et al. 8411 (ALA, BABY, CAN, MT, O), Ponomarenko VI-088 (CAN), Stephens 1199 (CAN, KANU). Ferguson L. [Tahiryuaq]: Hainault 2078 (DAO). Greiner L.: Ponomarenko VI-100B, VI-110, VI-135c, VI-178, VI-189A, VI-315 (CAN). Johansen B.: Gillespie et al. 7914 (ALA, CAN, MT, O). Sinclair Cr.: Gillespie et al. 8337 (CAN).

Carex maritima Gunnerus, Figs 15B, Figs 14E–Maritime sedge | Circumpolar-alpine

Previously recorded from Albert Edward B., Cambridge Bay, Hadley B., Kuujjua R., the head of Minto Inl., Mt. Pelly, Namaycush L., the head of Prince Albert S., Read I., Richard Collinson Inl. and Ulukhaktok (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.) and Wellington B. Newly recorded from Albert Edward B., Boot Inl., Clouston B., Greiner L., Kuujjua R. and Oterkvik Pt. Elsewhere in the Canadian Arctic recorded from Baffin, Banks, Coats, Devon and Southampton islands, and across the mainland (Porsild and Cody 1980, Cody et al. 1989, Korol 1992, Cody et al. 2003, Aiken et al. 2007, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9651 (CAN, O). Kuujjua R.: Edlund 644 (CAN), Gillespie et al. 9943 (CAN, O). Minto Inl. (head): Edlund 132, 176 (CAN), Gillespie et al. 10228 (CAN, O, WIN), 10283 (ari, CAN). Prince Albert S.: Porsild 17435 (CAN). Richard Collinson Inl.: Edlund 691 (CAN). Ulukhaktok: Edlund 347, 457, 775 (CAN), Porsild 17250 (CAN), Saarela & Bull 1457 (ALA, CAN, O). NUNAVUT. Albert Edward B.: Edlund 12746 (CAN, TRTE), Ponomarenko VI-336A (CAN). Cambridge Bay: Bennett et al. 13-0163 (ALA, BABY, CAN, chars, UBC), Consaul & Gillespie 1120 (CAN), Edlund & Argus 12692 (CAN), Gillespie et al. 8370, 8491 (CAN, O), Oldenburg 44-924 (CAN), Polunin s.n. (CAN), Porsild 21601 (CAN), Stephens 1142 (CAN). Clouston B.: Gillespie et al. 7750 (ALA, CAN, O). Greiner L.: Ponomarenko VI-035C, VI-291A (CAN). Hadley B.: Edlund 113 (CAN). Johansen B.: Gillespie et al. 7917 (ALA, BABY, CAN, MT, O, UBC, US), 7908 (CAN, O), 8016 (CAN, O). Ovayok TP: Stephens 1184 (CAN). Murray Pt.: Gillespie et al. 8196 (CAN, O). Namaycush L.: Edlund 134, 135, 18, 31 (CAN). Oterkvik Pt.: Gillespie et al. 7613 (ALA, CAN, O). Read I.: Oldenburg 42-487, 42-492, 43-1009, 43-882, 43-884, 43-966 (CAN), Porsild 17188 (CAN).

Carex membranacea Hook., Figs 15C, 14F–Fragile sedge | Amphi-Beringian–North America (N)

Previously recorded from Byron B., C. Wollaston, Ferguson L., Kuujjua R., Mt. Bumpus, Natkusiak P., the head of Prince Albert S., Richard Collinson Inl., Tahiryuaq and Ulukhaktok (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Ford and Ball 1992, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.), Richardson I., Surrey L. and Wellington B. Newly recorded from Albert Edward B., Boot Inl., Falaise B., Ferguson L., Murray Pt., Oterkvik Pt., Namaycush L., an inland site on Prince Albert P., Read I., Sinclair Cr., Tuktu R., Walker B. and Washburn L. Widespread throughout the Canadian Arctic (Porsild and Cody 1980, Cody et al. 1989, Ford and Ball 1992, Korol 1992, Aiken et al. 2007, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9551 (ALA, ari, CAN, MT, O, UBC). C. Wollaston: Edlund 35, 51, 150 (CAN). Kuujjua R.: Edlund 635 (CAN), Gillespie et al. 9727 (ALA, CAN, MT, O). Minto Inl. (head): Edlund 90, 133 (CAN), Gillespie et al. 10036 (ALA, CAN, MT, O), 10037 (ALA, ari, CAN, MT, O, UBC, WIN), 9493 (ALA, CAN, O), Porsild 17367 (CAN). Prince Albert P.: Oldenburg 54-658 (UBC). Prince Albert S. (head): Edlund 382 (CAN). Richard Collinson Inl.: Edlund 676, 690 (CAN). Tahiryuaq: Edlund 401 (CAN). Ulukhaktok: Edlund 717, 908 (CAN), Oldenburg 42-71, 45-1575, 45-1580 (CAN), Saarela & Bull 1481 (ALA, CAN, O), 1499 (ALA, CAN, O). Walker B.: Oldenburg 45-1428, 45-1429, 45-1432B (CAN). NUNAVUT. Albert Edward B.: Ponomarenko VI-268 (CAN). Byron B.: Dushenko (UVIC). Cambridge Bay: Bennett et al. 13-0181 (CAN, chars, od), Calder et al. 24166 (DAO), Consaul & Gillespie 1107, 1126 (CAN), Edlund & Argus 12622 (CAN), Gillespie et al. 8361 (ALA, CAN, O), Oldenburg 44-918, 44-959 (mixed with Carex saxatilis) (CAN), Polunin s.n. (CAN, 2 sheets), Ponomarenko VI-080B (CAN), Porsild 17465, 21514 (CAN), Stephens 1151 (CAN), Thomson s.n. (WIS). Falaise B.: Eriksen et al. 967 (ALA). Ferguson L. [Tahiryuaq]: Hainault 2065, 2066 (DAO), Jones & Hainault 1862 (DAO). Greiner L.: Ponomarenko VI-100F, VI-101a, VI-110A, VI-110B, VI-110C, VI-125, VI-130b, VI-170, VI-225, VI-229, VI-241B, VI-295A, VI-323 (CAN). Johansen B.: Edlund & Argus 12781 (CAN, TRTE), Gillespie et al. 7945 (ALA, ALTA, BABY, CAN, MT, O, UBC, US). Mt. Bumpus: Edlund 219 (CAN). Mt. Lady Pelly [Amaaqtuq]: Jones & Hainault 34a (DAO). Ovayok TP: Stephens 1162 (CAN). Murray Pt.: Gillespie et al. 8204 (ALA, CAN, O). Namaycush L.: Edlund 32 (CAN). Natkusiak P.: Edlund 332 (CAN). Oterkvik Pt.: Gillespie et al. 7555 (ALA, BABY, CAN, MT, O, US), 7646 (CAN, O), 7791 (ALA, CAN, O). Read I.: Oldenburg 42-488, 43-1007, 43-889, 43-922, 43-944, 45-1578 (CAN). Sinclair Cr.: Gillespie et al. 8300 (ALA, BABY, CAN, MO, MT, O, UBC, US). Tuktu R.: Gould s.n. (ALA). Washburn L.: Oldenburg 46-2223, 46-2224, 46-2228 (CAN).

Carex microglochin Wahlenb., Fig. 15D–Bristle sedge | American Beringian–North American–amphi-Atlantic–European (N/C) & Asian (C)

Previously recorded from Ulukhaktok (Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Johansen B. (conf.). In this area we found the species growing in a wet sedge meadow near the mouth of Mackenzie Creek; it was uncommon. Newly recorded from Clouston B., where it grew in wet mud at the edge of a dried up pond. Elsewhere in the Canadian Arctic recorded from southern Baffin and Banks islands and a few mainland sites (Polunin 1939, Porsild and Cody 1980, Aiken et al. 2007, Saarela et al. 2013, Saarela et al. 2017b). The scattered sites across the southern portion of the Canadian Arctic Archipelago mark the northern limit of the species in Canada.

NORTHWEST TERRITORIES. Ulukhaktok: Edlund 771, 822 (CAN). NUNAVUT. Clouston B.: Gillespie et al. 7751 (CAN), 7754 (CAN, O). Johansen B.: Gillespie et al. 8108 (ALA, CAN, MT, O).

Carex myosuroides Vill. (Kobresia myosuroides (Vill.) Fiori.), Figs 15E, 16A, B–Mouse-tail bog sedge | Circumpolar-alpine

Figure 16. 

A Carex myosuroides habit B Carex myosuroides habitat C Carex petricosa subsp. petricosa habit, Gillespie et al. 9657 D Carex petricosa subsp. petricosa habitat, Gillespie et al. 9657. Photos A, B by B.A. Bennett and C, D by J.M. Saarela.

Porsild (1955) reported this taxon from Read I., three sites (Wollaston P., Ulukhaktok [conf.] and Minto Inl. [conf.]) for which he did not cite specimens, and noted observations of the species at Walker B. (conf.), the head of Prince Albert S. and Cambridge Bay. He subsequently mapped the species at all these sites (Porsild 1957, 1964, Porsild and Cody 1980). Aiken et al. (2007) recorded it from Anderson B., Cambridge Bay, Mt. Bumpus, Ulukhaktok and Kuujjua R. Thannheiser et al. (2001) additionally recorded it from Mt. Pelly, Surrey L. and Wellington B. Newly recorded from Boot Inl., Greiner L., Natkusiak P., Oterkvik Pt., an inland site SE of the head of Prince Albert S., Richard Collinson Inl., Tahiryuaq, Sinclair Cr. and Washburn L. Elsewhere in the Canadian Arctic recorded from Baffin, Banks, Devon, Ellesmere, Melville, Somerset and Southampton islands, as well as a few mainland sites (Porsild and Cody 1980, Aiken et al. 2007, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9544 (ALA, CAN, O, WIN). Burns L. (S): Edlund 74 (CAN). Kuujjua R.: Gillespie et al. 9723 (ALA, CAN, MT, O), Dutilly 18818 (DAO). Minto Inl. (head): Edlund 102 (CAN), Gillespie et al. 9495 (ALA, ari, CAN, MT, O, UBC), 10156 (ALA, CAN, O, WIN). Natkusiak P.: Edlund 170 (CAN). Richard Collinson Inl.: Edlund 682 (CAN). Tahiryuaq: Edlund 561, 562 (CAN). Ulukhaktok: Edlund 337, 432, 444, 469, 660, 770, 860 (CAN), Saarela & Bull 1417 (CAN, O). Walker B.: Oldenburg 45-1409 (CAN). NUNAVUT. Anderson B.: Edlund & Argus 12719 (CAN). Cambridge Bay: Bennett et al. 13-0241 (chars, od), Calder et al. 24211 (DAO), Dutilly 28096 (US), Edlund & Argus 12880 (CAN), Gillespie et al. 8360 (ALA, CAN, MT, O), Gould s.n. (ALA), Polunin s.n. (CAN, 2 sheets), Porsild 21609 (CAN), Stephens 1106 (CAN, KSTC). Clouston B.: Gillespie et al. 7742 (ALA, CAN, MT, O). Greiner L.: Ponomarenko VI-145 (CAN), Johansen B.: Gillespie et al. 7835 (ALA, CAN, MT, O), 8086 (ALA, BABY, CAN, MT, O, UBC, US), 8147 (CAN, MT, UBC), 7909 (CAN, O). Mt. Bumpus: Edlund 232, 42 (CAN). Namaycush L.: Edlund 42, 164 (CAN). Oterkvik Pt.: Gillespie et al. 7487 (ALA, BABY, CAN, MT, O, US), 7547 (ALA, ALTA, BABY, CAN, MT, O, UBC, US), 7552 (ALA, CAN, MT, O), 7618 (ALA, BABY, CAN, MT, O), 7579 (ALA, CAN, O), 7581 (CAN). Sinclair Cr.: Gillespie et al. 8303 (ALA, CAN, O). Read I.: Oldenburg 43-1010, 43-885, 43-891 (CAN), Porsild 17191 (CAN). Washburn L.: Oldenburg 46-2221 (CAN).

Carex nardina Fr. (C. nardina var. atriceps Kük.), Fig. 15F–Nard sedge | Amphi-Beringian–North American–amphi-Atlantic (W)

Previously recorded from Mt. Bumpus, and Walker B. (Porsild 1955, 1957, 1964, Porsild and Cody 1980, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Cambridge Bay, Johansen B., Mt. Pelly, Ulukhaktok (conf.) and Wellington B. Newly recorded from Boot Inl., Falaise B., Ferguson L., Hadley B., Kuujjua R. and the head of Minto Inl. Elsewhere in the Canadian Arctic recorded from Baffin, Banks, Devon, Ellesmere, Mansel, Melville, Nottingham and Southampton islands, as well as mainland sites (Porsild and Cody 1980, Cody et al. 1989, Cody and Reading 2005, Aiken et al. 2007, Saarela et al. 2013, Saarela et al. 2017b).

NORTHWEST TERRITORIES. Boot Inl.: Gillespie et al. 9666 (ALA, ari, CAN, MT, O, UBC). Kuujjua R.: Gillespie et al. 9966 (ALA, CAN, MT, O). Minto Inl. (head): Gillespie et al. 10221 (ALA, CAN, MT, WIN), 9506 (ALA, CAN, O), 9789 (ALA, ari, CAN, MT, O). Ulukhaktok: Svoboda 745004 (TRTE, UBC). Walker B.: Porsild 17485 (CAN). NUNAVUT. Falaise B.: Eriksen et al. 997 (ALA). Ferguson L. [Tahiryuaq]: Bennett et al. 14-0430 (BABY). Hadley B.: Edlund 81 (CAN). Mt. Bumpus: Edlund 274 (CAN).

Carex petricosa Dewey subsp. petricosa (Carex petricosa var. petricosa), Figs 15G, 16C, D–Rock-dwelling sedge | Amphi-Beringian–Cordilleran & North America (NE)

A rare taxon known in the Canadian Arctic Archipelago only from western Victoria I., previously recorded from Walker B. (Porsild 1955, Aiken et al. 2007). Thannheiser et al. (2001) additionally recorded it from Ulukhaktok. A site to the north of Walker B., mapped in Aiken et al. (2007) based on the map in Porsild and Cody (1980), is likely a misrepresentation of the Walker B. collection. A site on the north shore of Prince Albert S. was mapped by Ball and Zoladz (1994); we have not seen a voucher. Newly recorded from Falaise B., Boot Inl., the head of Minto Inl. and Kuujjua R. At the last three sites this rhizomatous taxon grew in dry rocky tundra and slopes typically associated with