Flora of the Canadian Arctic Archipelago


S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, L.J. Gillespie, A.K. Brysting, H. Solstad, and J.G. Harris

Dryas integrifolia Vahl

English: Mountain avens,

French: Dryade à feuilles entières,

Inuktitut: Malikkaat (Pangnirtung), isuqtannguat (Cape Dorset), isurramuat, qasilinnait, or atungaujat, alatsaujat, piluit.

Rosaceae, Rose family.

Published in Skr. Naturhist.-Selsk. 4, 2: 171. 1798.

Type: Described from Greenland.

Synonymy. Dryas integrifolia Vahl var. canescens Simmons, Vasc. Pl. Ellesmereland 46. 1906.

Dryas integrifolia Vahl f. canescens (Simmons) Fernald, Rhodora 35: 273. 1933.

Dryas integrifolia Vahl f. intermedia (Nath.) Polunin, J. Bot. 76: 101. 1938.

Vegetative morphology. Plants (2–)5–15(–17) cm high; shrubs; dwarf shrubs. Poorly developed lateral roots, developed along the branches, may be present on herbarium specimens. Horizontal stems at ground level, branching extensively to shape plant habit as mats. Aerial stems prostrate. Leaves present; distributed along the stems; alternate; marcescent. Stipules present; 12–18 mm long; 1.5–2.5 mm wide; not sheathing; green (when very young), or brown (with age); hairy; short-silky; apex acuminate. Petioles present; 1–10(–15) mm long; hairy; villous, or woolly, or long-silky. Petiole hairs longer than the diameter of the petiole; spreading; straight, or wavy; rough. Leaf blades simple (a contrast with other Arctic members of the family). Leaf blade bases cordate (slightly), or truncate. Blades 5–22 mm long, (1–)2–4(–6) mm wide, linear or oblong or lanceolate (narrowly triangular at least towards the apex), flat or revolute (just at the margins or involving most of the leaf blade), veins pinnate. Blade adaxial surface without sessile glands, glabrous. Blade abaxial surface hairy, hairs tomentose (between the veins) or long-silky (along the midvein), hairs very dense, hairs white, hairs wavy, hairs spreading. Blade margins slightly revolute or strongly revolute. Blade margins entire or crenate (slightly) or revolute (to varying degrees), glabrous or with non-glandular hairs, with teeth toward the base (mainly); apices acuminate, or acute. Leaflets veins conspicuous.

Reproductive morphology. Flowering stems two or more per plant; conspicuously taller than the leaves; without leaves. Flowering stems hairy. Flowering stems woolly. Flowering stem hairs simple; longer than the diameter of the flowering stem; white or translucent; glandular hairs present (usually some, but with more non-glandular hairs present). Flowers solitary. Flowers medium-sized, or large. Sepals conventional. Epicalyx absent. Sepals 7–8; free; 1.5–3 mm long; 3–9 mm wide; green, or brown, or black. Calyx hairy (at the tips of the sepals). Calyx hairs woolly (with conspicuous black glandular hairs usually: some plants collected on Baffin Island lack the black glandular hairs on the calyx); glandular; white or translucent (rarely), or brown, or black. Petals conventional; free; 7–11; white, or yellow (cream); ovate, or obovate; unlobed; 5–13 mm long; 5–10 mm wide. Stamens 40–70; stamen filaments glabrous. Anthers yellow; sub-globose; 0.2–0.3 mm long. Ovary superior; carpels 20–40; apocarpous. Styles 3–5 mm long (in flower, elongating in fruit); conical; basal portion with hairs at the base. Ovules per ovary 1. Fruit sessile; with calyx persisting; dry; an aggregate of achenes; obovate; brown, or straw-coloured; 2–5 mm long (without stigmas); hairy; surface appearing veinless (obscured by hairs); indehiscent. Styles modified and persisting (elongated to 1.5–2.5 cm; initially styles are intertwined and twisted, unwinding as the fruits mature); becoming plumose (becoming fluffy from long hairs on the style).

Chromosome information. 2n = 18.

2n (2x) = 18. Böcher and Larsen (1950, Greenland); Löve (1954b); Packer (1964, western Canada, perhaps 'sylvatica'); Elkington (1965, Greenland); Zhukova (1965a, Chukotka as D. chamissonis; 1966, northeastern Asia; 1982, northeastern Asia, as D. chamissonis); Mosquin and Hayley (1966, northern Canada); Hedberg (1967, northern Canada); Packer and McPherson (1974, northern Alaska); Löve and Löve (1982a, Arctic Canada).

Ploidy levels recorded 2x.

Indigenous knowledge. Some Inuit names are malikkaat, isuqtannguat, isurramuat, and piluit. The word malikkaat is used in Panniqtuuq (Pangnirtung), while isuqtannguat is used in Kinngait (Cape Dorset). According to their etymology, these plants are called malikkaat because they follow the seasons. The word isurramuat refers to the fact that they follow the path of the sun. These plants are said to indicate the seasons: when summer is coming they fold out in one direction, and when winter is coming they fold in and twist in the other direction (Ootoova et al. 2001). Piluit is the dye and seeds of avens.

The leaves may be called qasilinnait, or atungaujat, and may also be known as the plant that numbs the tongue (Ootoova et al. 2001). Atungaujat in Iglulik are leaves of mountain avens. In some communities in South Baffin the term is used for grilled mushrooms. In some communities in both North and South Baffin, it refers to leaves that seem to sprout individually right from the ground, are reddish in colour, and shaped like willow leaves. These leaves are known as alatsaujat in other communities.

Mountain avens plants were used to determine the seasons, particularly in the summer. When they are curled tightly it means it is midsummer. As soon as they start to uncoil it is the approach of autumn (Lucien Ukaliannuk, personal communication, in Mallory and Aiken 2004). These plants were called mannik in the spring when birds start to lay eggs and saggaruut at the next stage when the hairs on the caribou had moulted and been replaced by thin hair. Akkulliruut was the name given when the fruits start to uncoil (Michel Krpaaq, personal communication, in Mallory and Aiken 2004). Eva Aariak (personal communication, 2006) noted that the words mannik, saggaruut, and akkulliruut are names of months rather than names applied to this species in particular. When the seed heads are tightly twisted, caribou skins are too thin to make clothing. As the seed heads untwist, caribou skins are suitable for women's clothing. When the seed heads are fully open, caribou skins are suitable for men's clothing.

Ecology and habitat. Substrates: wet meadows (rarely, e.g., CAN 264266), depressions of low-centre polygons (occasionally, e.g., CAN 74268), river terraces, tundra, slopes, ridges; imperfectly drained moist areas (rarely), dry, moderately well-drained areas; rocks, gravel, sand, silt, clay; with low organic content.

North American distribution. A ubiquitous pioneer species of frost-heaved, calcareous, gravelly, and rocky barrens, and in the western islands it probably is the most common and widespread flowering plant. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago widespread. Common. Arctic. Arctic islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry islands (Bathurst, Emerald, Melville, Prince Patrick), Cornwallis, Banks, Victoria (Steffanson), Prince of Wales, Somerset, King William, Southampton, Coats (Air Force, Digges, Prince Charles, Resolution, Lower Savage, Salisbury and Melville peninsulas).

Northern hemisphere distribution. Amphi-Beringian, or North American. West Chukotka, Wrangel Island, South Chukotka, East Chukotka, West Alaska, North Alaska – Yukon, Central Canada, Labrador – Hudson Bay, Ellesmere Land – Peary Land, West Greenland, East Greenland.

General notes. Porsild (1947) indicated that D. integrifolia in North America is by far the most common and widespread member of the genus, and in postglacial time has reoccupied nearly all land surface in the Arctic once occupied by ice. It is an arctic-alpine species, which within its main area is an ubiquitous pioneer species in rocky and gravelly places such as river flats and screes, but less common in dwarf shrub heath where it is rapidly out-competed for space. Dryas integrifolia fruits abundantly, and its immature achenes form an important food item for numerous species of small rodents and for several species of birds.

Porsild (1947) stated that D. integrifolia seems to be entirely lacking in ecotypes, an opinion that might be debated based on specimens from the Canadian Arctic Archipelago. He noted that D. integrifolia from Greenland, D. octopetala s.s. from Europe, and D. drummondii from the Canadian Rockies have long been grown commercially and in botanical gardens. They have all preserved their characteristics, and there is little reason to expect that fundamental characters such as the presence or absence of glands would be controlled by ecological variables. He also noted that it would be of considerable interest to grow in cultivation many of the other taxa that have been recognised in the genus. However, many of them occur in inaccessible areas, and fresh seed material cannot be easily procured.

Juzepchuk (1919, 1929) provided a comprehensive treatment of the genus Dryas chiefly dealing with Asiatic plants. Porsild (1947) wrote on the genus in North America, extending the treatment by Juzepczuk to areas in North America where that author had few specimens to work with. A summary of the structure in the genus, as seen by current Russians, is presented by Yurtsev (1997). These authors recognised the subgeneric entities following within the genus:

Section or subgenus Nothodryas Juz. has leaves pointed at the base; petals and sepals erect-spreading or quite erect during flowering and receptacles flattened, species D. drummondii and D. grandis;

Section or subgenus Eudryas Juz., leaves mostly rounded, truncate or sub-cordate at the base; petals and sepals spreading during flowering, receptacles convex.

Within Eudryas the Russian authors recognised the following sub-sections:

Subsection Dryas, leaves dentate, without punctiform glands, but with feathery hairs ('octopetala scales') along the lower leaf surface midvein, no glandular hairs on the lower surface midvein, e.g., species D. octopetala and D. ajanensis.

Subsection Incisae Jurtz., leaves crenate or dentate throughout, without punctiform glands, glandular hairs, or feathery hairs, e.g., D. incisa.

Subsection Tenellae Juz., leaves entire or crenate in basal part only, without punctiform glands, glandular hairs, or feathery hairs, e.g., D. integrifolia.

Subsection Punctatae Juz., leaves dentate, with punctiform glands, glandular hairs along the lower leaf midvein, but generally without feathery hairs, e.g., D. punctata and D. alaskensis.

Porsild (1947) and Hultén (1959a) considered Dryas as an old holarctic genus that is particularly interesting for studies in phytogeography and phylogeny. Dryas octopetala is thought to have once had a complete circumpolar distribution reaching North America from Alaska south to Colorado and east to northeastern Greenland. Hultén (1959a) considered Dryas to be a tertiary genus that early differentiated into three types, two closely related, D. octopetala and D. integrifolia, and the third more differentiated, D. drummondii, which occurs in western continental North America, and possibly a fourth, D. grandis, which occurs in Eastern Russia. He stated that both D. octopetala and D. integrifolia are probably fairly old and must have existed before the glacial period. During the glacial period, southern isolated populations of D. octopetala also occurred in central Europe, in the Caucasus, in Japan, and in the Rocky Mountains, where more or less different races were developed and still remain isolated in most cases.

Considering the Canadian Arctic Archipelago, Hultén (1959a) stated that this is where D. integrifolia is presumed to have survived the glacial period and to have hybridised with D. octopetala so strongly that today only a remnant of the hybrid is left, while in eastern Greenland D. octopetala still survives, although a large part of its population apparently shows the hybrid influence of D. integrifolia in lacking octopetala scales.

Hultén (1959a) considered hairs, glands, and scales on the leaves are very good characters for identifying the different races within the D. octopetala complex, while the form of the leaves and other characteristics used for that purpose he considered less reliable. He described octopetala scales as long, narrow, more or less flat brownish coloured tuft-like scales, built up of several rows of cells with white hairs on their margins. The scales occur on the underside of the leaves on the leaf mid-nerve and to a lesser extent on the lateral nerves. Hultén (1959a) commented that it is remarkable that octopetala scales, which are so significant for some taxa, can be missing where they would be expected and occur where they are not expected. For example, D. octopetala-like taxa lacking octopetala scales occur in Alaska and in East Greenland.

Hultén (1959a) offered the opinion that D. integrifolia is supposed to have occurred in the Rocky Mountains, south of its present range and also in eastern Asia westwards to Lake Bajkal, but was so strongly influenced by D. octopetala there that only hybrids remain today, except in the northeastern corner of Asia where D. integrifolia still occurs. In unglaciated Alaska and Yukon, races of both D. integrifolia (subsp. sylvatica Hultén) and D. octopetala (subsp. alaskensis Porsild) developed during the glacial period. There the areas of at least six different entities (not counting D. drummondii) overlap and cross more or less freely and can only more or less arbitrarily be distinguished from each other. Cody (1996) provides a key to these taxa. Hultén (1959a) provided a key to taxa and hybrids that he recognised.

In the Canadian Arctic Archipelago, Hultén (1959a) recognised D. integrifolia Vahl subsp. integrifolia ×octopetala L., citing specimens collected from Southampton Island and Prince Patrick Island, but subsequent authors have not recognised this hybrid.

Nordal et al. (1999) held a workshop to discuss a proposed treatment of the genus Dryas for the Panarctic Flora Checklist (Elven et al. 2003). Yurtsev (1984, 1997) recognised 15 species in the genus globally and of these nine reach the Arctic. The taxa are mainly defined and delimited by characters from indumentum, glands (presence/absence and types), and leaf shape, incision, and structure. The workshop provided a modified translation of the key given by Yurtsev (1997), with hybrid combinations that he proposed removed. The discussions concerned the interpretation of the morphological variation and its taxonomic significance, especially the use of single characters and of the assumptions of hybridogenous origins of taxa with intermediate features. No consensus was reached. The conclusion was that here is an obvious need for modern analyses of both arctic and non-arctic Dryas, involving both more extensive morphological analyses, investigation of molecular markers, and further application of eco-geographic methods.

The common name 'mountain avens' is also used for the species Dryas octopetala in northern Europe.

The flowers of Dryas are heliotropic and face the sun as it moves across the horizon. The flower sepals in bud often appear black from the many coarse hairs that may be glandular-tipped. Occasionally, these hairs are absent and the sepals appear grey-green (see, for example, Baffin Island, Camp Kungovik, J.D. Soper 125996, 15 July 1929. CAN 74264).

Illustrations. • Habitat in Low Arctic tundra. Plants with white flowers in the background growing with fireweed in Low Arctic tundra. Nunavut, Baffin Island, Cape Dorset. 2 August, 2005. Aiken. No voucher. • Habitat: Cape Dorset. Plants growing in gravelly tundra with Oxytropis maydelliana. Nunavut, Baffin Island, Cape Dorset. 2 August, 2005. Aiken. No voucher. • Habitat: High Arctic. Soil polygon landscape in Northern Arctic Tundra Zone, with Dryas octopetala, a European species, in all the cracks. Norway, Svalbard, Siklarhallet. August, 1997. Photograph by R. Elven. • Plant habit: Banks Island. Lush flowering plants growing in a sheltered gully. N.W.T., Banks Island, Sachs Harbour. 27 July, 1981. J.M. Gillett 18857. CAN. • Surface view of leaves. Upper leaf, note hairy stipules at the base of the petiole and a deep green upper surface to the leaf. Lower leaf showing light green "duffle-coated" undersurface. Nunavut, Baffin Island, Iqaluit. Aiken 2002. No voucher. • Adaxial leaf surface. Waxy surface to the leaf and veins sunk into the surface. These features help prevent tissue from drying out. Note small glands on the leaves and a stipule (s) at the base of the petiole. Photograph by Carolyn Mallory, 2003. No voucher. • Abaxial leaf surface. Note recurved margins and dense hairs on the surface that act like a fur fringe around a hood to limit air movement over the stomates (breathing leaf pores) that are on this surface. 2003. Photograph by Carolyn Mallory. No voucher. • Close-up of bud: Western Arctic, Banks Island. Flower in bud with glands on the sepals of buds. Note the sepals also have reddish black hairs, that possibly aid in warming the developing flower. Banks Island, Aulavik National Park, near Green Cabin. June 29, 1999. Aiken. CAN. • Close-up of bud: Eastern Arctic, Baffin Island. Bud on plant from Eastern Arctic. Note the hairs are conspicuously paler and not as obviously glandular as those on plants from the western Arctic. Nunavut, Baffin Island, Iqaluit. August, 2005. Aiken. No voucher. • Close-up of plants: Banks Island. Note plants in three stages of flowering: flowers in bud, flowering (with petals) and past flowering (without petals). Banks Island, Aulavik National Park, near Green Cabin. 13 July, 1999. Aiken 99–064. CAN. Scale bar in cm. • Close-up of flowers. Prostrate woody shrub in flower. Note flowers heliotrophic. N.W.T., Banks Island, Sachs Harbour. 27 July, 1981. J.M. Gillett 18857. CAN. • Close-up of flower. Flower with ripening anthers around the immature gynoecium. Nunavut, Baffin Island. 2005. Aiken. No Voucher. • Side view of flower. Note anthers around the free stigmas that are emerging in the centre of the flower. Nunavut, Baffin Island. 2005. Aiken. No Voucher. • Close-up of flower. Flower with a few dehisced but mainly pre-anthesis anthers. Note centre of flower with numerous styles from individual carpels born on a hypogynous receptacle. Nunavut, Baffin Island. August, 2005. Aiken. No voucher. • Fly pollination. Fly actively foraging on Dryas flower that is almost completely open. Nunavut, Baffin Island, Soper River Valley. Aiken 2002. No voucher. • Close-up of flower without petals. Flower approximately 1 cm in diameter after the petals have been shed. The inner surface of the sepals is pale green, there is a ring of numerous anthers, and twisted styles in the centre. Banks Island, Aulavik National Park. 3 July, 1999. Aiken 99–064. CAN. • Plant in fruit. Note flowering stalks that have elongated after flowering, glandular hairs on the calyces, and the modified styles that have enlarged as fruit develops. N.W.T., Tuktoyaktuk. 21 July, 1981. J.M. Gillett 18727. CAN. • Fluffy seed heads. Fruiting heads that are an aggregate of achenes at different stages of maturity. Note modified stigmas that vary from tightly twisted to untwisted, and fluffy. These assist with seed dispersal. Nunavut, Baffin Island, Iqaluit. August, 1986. Aiken. No voucher. • Close-up of flowering head. Arrows (a) point to small yellow achenes that are the fruit of the apocarpous gynoecium. The long whitish tops to each achene are accrescent plumose styles that have developed and assist with seed dispersal. 2003. Photograph by Carolyn Mallory. No voucher. • Arctic Island Distribution.

This publication is available on the internet (posted May 2011) and on CD-ROM (published in 2007). These versions are identical in content, except that the errata page for CD-ROM is accessible on the main index page of the web version.

Recommended citation for the web-based version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. NRC Research Press, National Research Council of Canada, Ottawa. http://nature.ca/aaflora/data, accessed on DATE.

Recommended citation for the CD-ROM version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. [CD-ROM] NRC Research Press, National Research Council of Canada, Ottawa.