Salix polaris Wahlenb.
Polar willow.
Fl. Lapp. 261: 1812.
Salix polaris subsp. pseudopolaris (Flod.) Hultén
Salix polaris var. glabrata Hultén
Salix polaris var. selwynensis Raup
Salix pseudopolaris Flod
Plants dwarf shrubs; less than 15 cm high; 1–9 cm high; forming rhizomatous or stoloniferous mats. Stems. Aerial stems erect. Branches red-brown; thinly glaucous, or thickly glaucous; glabrous; epidermis not flaky. Branchlets brownish; not glaucous; glabrous. Bud scale inner membrane fused to outer layer. Stipules. Stipules present, or absent; scale-like. Petioles. Petioles 2–10 mm long; glandular dots at the base of the leaf absent; deeply concave in cross-section, but margins not covering the groove; glabrous. Leaves. Juvenile leaves yellowish green; glabrous. Blades 0.5–3.2 cm long; 8–18 mm wide; length-width ratio 1.1–2.8; herbaceous, or leathery; elliptic (to broadly elliptic), or obovate, or circular; flat; secondary veins protruding on adaxial and abaxial surfaces, or flat on adaxial surface, protruding on abaxial surface; secondary veins arising along midrib; stomata on both adaxial and abaxial surfaces. Blades adaxial surface shiny; glabrous (rarely ciliate distally). Blades abaxial surface glabrous (rarely with long straight hairs); not glaucous. Leaf bases acute, or cuneate, or obtuse, or attenuate. Leaf margins entire. Leaf apices rounded, or obtuse (sometimes), or acute.
Plants dioecious. Catkins. Catkins flowering with the opening of leaf buds; catkins terminal on previous year’s shoot, or one to several catkins just below tip of previous year’s shoot. Male catkins. Male catkins densely flowered; 6–27 mm long; 6–12 mm wide; stout, or subglobose, or globose; peduncles 1.5–9 mm long; borne on a flowering branchlet; flowering branchlets 1.5–14 mm long. Female catkins. Female catkins densely flowered, or moderately densely flowered; 10–35 mm long; 7–13 mm wide; stout, or subglobose, or globose; peduncles 2–12 mm long; borne on a flowering branchlet; flowering branchlets 1–12 mm long. Floral bracts. Floral bracts brown, or black, or bicolour; widest at middle, or widest toward tip; 1.5–2.5 mm long; hairy all over, or glabrous; hairs sparse; hairs straight, or wavy; entire. Stamens 2; filaments glabrous. Anthers purple becoming yellow; ellipsoid, or ovoid; axis straight; 0.4–0.6 mm long. Male flowers. Male flowers abaxial nectaries one, or absent (rarely); adaxial nectaries one; adaxial nectaries broad-rod, or slender-rod, or square, or ovate; adaxial nectaries 0.5–1.4 mm long (1.0); adaxial nectaries separate. Female flowers. Female flowers adaxial nectaries absent; unlobed; slender-rod, or broad-rod, or ovate; 0.8–1.4 mm long; longer than stipes. Stipes 0.2–0.7 mm long. Ovaries inverse club-shaped, or pear-shaped; ovary gradually tapering to style, or slightly bulged at the base of the style; glabrous, or hairy; ovary villous, or pilose (hairy distally, or bare only at base). Ovary hair in patches or streaks, or sparse, or moderately dense, or dense; white, or translucent; spreading; straight, or wavy; flattened (somewhat refractive). Styles 0.7–1.6 mm long. Stigmas slender-cylindrical; lobes 0.4–0.57–0.72 mm long. Ovules 10–12. Fruit. Fruit 4.8–7 mm long; glabrescent.
Chromosome inforamtion. 2n = 76 and 114. 4x Marklund in Floderus 1931 (origin unknown); ca 6x Engelskjon 1979 (Spitzbergen); 6x Yurtsev & Zhukova 1982; Zhukova, et al. 1977; Zhukova & Petrovsky 1971, 1972, 1975, 1976, 1977, 1980; Zhukova et al. 1973; Zhukova & Tikhonova 1973; Petrovsky & Zhukova 1983b (Russia). Ploidy levels recorded 4 & 6x.
Distribution. Northern hemisphere: Canada, United States, Eurasia. Canada: B.C., N.W.T. (Frank.) (old), N.W.T. (Mack.) (old), Yukon, N.W.T., Nunavut. USA: Ariz.
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.
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. Salix polaris: habit. Photo taken at Victoria Island, Cambridge Bay, Nunavut, by Laurie Consaul, July 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1130, CAN. • Habitat. Salix polaris: habitat. Photo taken at Victoria Island, Cambridge Bay, Nunavut, by Laurie Consaul, July 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1130, CAN. • Close-up of female catkin. Salix polaris. Note hairs on the underside of leaf. Photo taken at Victoria Island, Cambridge Bay, Nunavut. Voucher specimen: Laurie Consaul and Lynn Gillespie 1130. • Male plant. Salix polaris: a dwarf shrub growing in moss. Photograph taken at Sachs Harbour, Banks Island, N.W.T. by Jack Gillett, 24 July 1981. Voucher specimen: Jack Gillett 18793, CAN. • Female plant. Salix polaris: female plant with small elliptic leaves. Photograph taken at Sachs Harbour, Banks Island, N.W.T. by Jack Gillett, 24 July 1981. Voucher specimen: Jack Gillett 18793. • Female catkin. Salix polaris: female catkin. The ovaries are sparsely hairy. Leaves are broadly elliptic. Photo taken at Victoria Island, Cambridge Bay, Nunavut, by Laurie Consaul, July 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1130, CAN. • Arctic Island Distribution.
Cite this publication as: G.W. Argus, C.L. McJannet and M.J. Dallwitz (1999 onwards). ‘Salicaceae of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval.’ Version: 2nd November 2000. http://http://www.mun.ca/biology/delta/arcticf/. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
