Flora of the Canadian Arctic Archipelago
English: Polar willow.
Salicaceae, Willow family.
Published in Fl. Lapp. 261: 1812.
Type: Northern Sweden: Lapland, selected by Moberg and Nilsson, Nordic J. Bot. 11: 296. 1991. Lectotype: UPS: Thunberg Herbarium 23096.
Synonymy. Salix polaris Wahlenb. subsp. pseudopolaris (Flod.) Hultén, Lunds Univ. Arssk, n.f., Avd. 2, 39: 510. 1943.
Salix polaris Wahlenb. var. selwynensis Raup, Contr. Arnold Arb. 6: 144. 1934.
Salix pseudopolaris Flod., Sv. Vet. Akad. Ark. Bot. 20A(6): 8. 1926.
Vegetative morphology. Plants 1–9 cm high; shrubs; dwarf shrubs; forming colonies by rhizomes. Horizontal stems at ground level, branching extensively to shape plant habit as mats. Aerial stems erect. Branches red-brown; weakly glaucous, or strongly glaucous; glabrous. Branchlets brownish; not glaucous; glabrous. Buds arctica-type. Leaves present; mainly basal, or distributed along the stems; alternate; dying annually and non-persistent. Stipules present, or absent; on first leaves absent, or rudimentary; on leaves formed later in the season rudimentary. Petioles 2–10 mm long; deeply concave in cross section; glabrous. Juvenile leaves yellowish green; glabrous. Leaf blade bases obtuse, or rounded, or cuneate (slightly decurrent). Leaves not grass-like. Blades 5–32 mm long, length-width ratio 1.1–2.8, 8–18 mm wide, elliptic (to broadly elliptic) or obovate or circular (or subcircular). Blade adaxial surface shiny, glabrous. Blade abaxial surface not glaucous, glabrous (rarely pilose). Blade margins flat or slightly revolute. Blade margins entire and glandular-dotted (ciliate); apices acute, or rounded, or retuse.
Reproductive morphology. Plants dioecious. Inflorescences catkins. Pedicels absent. Catkins arising from sub-apical buds, or arising from lateral buds; flowering as leaves emerge. Male catkins 9–34 mm long; 6–12 mm wide; stout, or sub-globose, or globose; peduncles 1.5–9 mm long; borne on a flowering branchlet; flowering branchlets 1.5–14 mm long. Female catkins 10–50 mm long; 7–13 mm wide; stout, or sub-globose, or globose; peduncles 2–11 mm long; borne on a flowering branchlet; flowering branchlets 1–12 mm long. Floral bracts brown, or black, or bicolour; 1.5–2.5 mm long; hairy all over, or glabrous; hairs sparse; hairs straight, or wavy; apices rounded, or convex; apices entire. Flowers unisexual. Sepals absent. Petals absent. Stamens 2; stamen filaments glabrous. Anthers purple becoming yellow; ellipsoid, or ovoid; 0.4–0.6 mm long. Male flowers abaxial nectaries present. Male flowers adaxial nectaries oblong, or narrowly oblong, or square, or ovate; 0.5–1.4 mm long (1.0); nectaries distinct. Female flowers abaxial nectaries absent. Female flowers adaxial nectaries narrowly oblong, or oblong, or ovate; 0.8–1.8 mm long; longer than stipes. Ovary carpels 2. Stipes 0.2–0.7 mm long. Ovaries inverse club-shaped, or pear-shaped; gradually tapering to style, or slightly bulged below style; hairy; villous, or pilose (hairy distally, or bare only at base). Ovary hairs sparse, or moderately dense, or very dense; white; spreading; straight, or wavy; flattened (somewhat refractive). Styles 0.7–1.2 mm long. Stigma lobes 0.4–0.57–0.72 mm long. Ovules per ovary 12–17. Fruit a capsule; 4.8–7(–8.25) mm long; glabrous, or hairy.
Chromosome information. 2n = 114.
2n (6x) = 114. Zhukova and Petrovsky (1971, 1972, 1975, 1976, 1977, 1980, northeastern Asia); Zhukova et al. (1973, 1977, northern Siberia, also 2n = 200+); Zhukova and Tikhonova (1973, Chukotka); Vodopianova and Krogulevich (1974, northern Siberia); Krogulevich (1976a, northern Siberia); Engelskjøn (1979, Svalbard, 2n = about 112); Yurtsev and Zhukova (1982, northern Siberia); Petrovsky and Zhukova (1983a, one specimen with 2n = 90 was "quite possibly" S. polaris × S. ovalifolia), northeastern Asia; 1983b, northeastern Asia). The only European count was 2n = 76 (4x), reported by Marklund in Holmberg 1931, voucher specimen unknown.
Ploidy levels recorded 4x and 6x.
Ecology and habitat. A dwarf shrub of moist, mossy snowbeds, talus slopes, sides of depressed centre frost polygons, sedge meadows, and mud boils. Often on calcareous tills, and sandy marine silts.
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands. Arctic islands: Parry islands, Banks, Victoria.
Northern hemisphere distribution. Amphi-Beringian, or Siberian (Eurasian). Northern Fennoscandian, KaninPechora, Svalbard Franz Joseph Land, Polar Ural Novaya Zemlya, YamalGydan, Taimyr Severnaya Zemlya, AnabarOlenyok, Kharaulakh, YanaKolyma, West Chukotka, Wrangel Island, South Chukotka, East Chukotka, West Alaska, North Alaska Yukon, Central Canada.
General notes. Salix polaris is a dwarf species with underground stems (rhizomes). Its leaves are essentially entire and non-glaucous abaxially. Pistils are hairy and have a prominent style. Sometimes diminutive material of S. arctica resembles S. polaris, but they can be separated by the abaxial leaf surface being glaucous or non-glaucous, respectively.
Illustrations. • Habit. Dwarf shrub with underground stems (rhizomes) and entire elliptic to ovate leaves. Nunavut, Victoria Island, Cambridge Bay. July, 1997. Laurie Consaul 1130 and Lynn Gillespie. CAN. • Female plant. Female plant with small elliptic leaves. N.W.T., Banks Island, Sachs Harbour. 24 July, 1981. J.M. Gillett 18793. • Female catkin. The ovaries are sparsely hairy and the leaves are broadly elliptic. Nunavut, Victoria Island, Cambridge Bay. July, 1997. Laurie Consaul 1130 and Lynn Gillespie. CAN. • Close-up of female catkin. The ovaries are sparsely hairy. July, 1997. Laurie Consaul 1130 and Lynn Gillespie. CAN. • Close-up of male plant. Large clump of male plants at anthesis. Norway, Svalbard, Kap Thordsen. July, 1997. Photograph by R. Elven. • Male plant. A dwarf shrub growing in moss. N.W.T., Banks Island, Sachs Harbour. 24 July, 1981. J.M. Gillett 18793. CAN. • 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..