Salix arctophila Cock. ex Heller
Northern willow.
Cat. N. Amer. Pl. ed. 3, 89. 1910.
Salix arctica Liebm., non Pallas
Salix arctophila var. lejocarpa (Lange) Schneid.
Salix groenlandica Lundstr., non Heer
Salix groenlandica var. lejocarpa Lange
Plants dwarf shrubs; less than 15 cm high; 3–15 cm high; forming colonies by layering. Stems. Aerial stems decumbent, or prostrate. Branches yellow-brown, or red-brown (greenish brown); not glaucous, or thinly glaucous; glabrous; epidermis not flaky. Branchlets yellow-green, or yellow-brown, or red-brown; not glaucous, or thinly glaucous; glabrous, or hairy; pilose (sparse). Bud scale inner membrane free but not separating from outer membrane. Stipules. Stipules present, or absent; leaf-like, or scale-like; apex acute. Petioles. Petioles 3–13 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, or hairy; abaxial surface pubescent; hair sparse; hair white. Blades 1.7–3.7 cm long; 7–16 mm wide; length-width ratio 1.2–1.8(–4.3); herbaceous, or leathery; elliptic (to subcircular), or obovate (to broadly obovate); revolute; secondary veins protruding on adaxial and abaxial surfaces; secondary veins arising along midrib; stomata only on abaxial surface, or stomata on adaxial surface only present along veins or at apex. Blades adaxial surface shiny, or highly glossy; glabrous. Blades abaxial surface glabrous; glaucous. Leaf bases obtuse, or acute, or cuneate. Leaf margins entire, or glandular-dotted, or serrulate (rarely with glandular teeth); with teeth all around leaf, or toward base only; with teeth per cm 1–8 (5); with marginal glands, or with submarginal glands. Leaf apices retuse, or rounded, or acute.
Plants dioecious. Catkins. Catkins flowering with the opening of leaf buds; one to several catkins just below tip of previous year’s shoot. Male catkins. Male catkins densely flowered, or moderately densely flowered; 17–50 mm long; 7–16 mm wide; slender, or stout; peduncles 2–6 mm long; borne on a flowering branchlet; flowering branchlets 4–15 mm long. Female catkins. Female catkins densely flowered, or moderately densely flowered; 16–116 mm long; 10–20 mm wide; slender, or stout; peduncles 4–24 mm long; borne on a flowering branchlet; flowering branchlets 8–57 mm long. Floral bracts. Floral bracts brown, or black, or bicolour (purplish red); widest at middle; 0.8–2.4 mm long; hairy all over; hairs moderately dense, or very dense; hairs straight; entire. Stamens 2; filaments glabrous, or hairy on lower half. Anthers purple becoming yellow; ellipsoid, or slender-cylindrical; axis twisted; 0.5–0.7 mm long. Male flowers. Male flowers abaxial nectaries absent; adaxial nectaries one; adaxial nectaries broad-rod, or square, or slender-rod, or ovate; adaxial nectaries 0.4–1 mm long. Female flowers. Female flowers adaxial nectaries absent; unlobed; broad-rod, or slender-rod (sometimes bifid); 0.5–0.9 mm long; shorter than stipes. Stipes 0.8–1.4 mm long. Ovaries pear-shaped, or inverse club-shaped; ovary gradually tapering to style, or slightly bulged at the base of the style; glabrous, or hairy; ovary puberulent, or hairs short-silky (dusty look). Ovary hair sparse; white, or translucent, or mixture of white, or translucent, and rust-coloured (refractive); appressed; wavy, or crinkled; ribbon-like, or flattened. Styles 0.6–1.4 mm long. Stigmas slender-cylindrical, or broad-cylindrical; lobes 0.24–0.47–0.72 mm long. Ovules 12–16. Fruit. Fruit 5–9 mm long; hairy, or glabrescent.
Chromosome inforamtion. 2n = 76. Jorgensen, Sorensen, & Westergaard 1958; Löve & Löve 1982. Ploidy levels recorded 4x.
Distribution. Northern hemisphere: Greenland, Canada, United States. Canada: Lab., Man., Nfld., Ont., Que., Sask., Yukon, N.W.T., Nunavut. USA: Alaska, Maine.
Ecology and habitat. A prostrate shrub, often with long, trailing stems. Often on hummocks, in wet, mossy, grass or sedge tundra meadows. Common along the edges of streams or ponds, among granitic boulders, on alluvial plains, or sometimes in snow beds.
Notes. Salix arctophila is a dwarf shrub with long trailing, glabrous branches, branchlets and leaves. Its leaves are usually sparsely toothed, and ovaries are puberulent to sparsely silky with flat, crinkled, ribbon-like hairs.
Hybrids
Salix arctica × arctophila (Polunin 1940). There are a number of putative hybrids in Canadian Museum of Nature from Baffin and Ellesmere islands. These plants have leaves and branchlets almost glabrous as in S. arctophila, but bearing only a few long hairs, and ovaries with flattened, refractive hairs as in S. arctica, not ribbon-like as in S. arctophila. On Bylot Island Drury (1962: 88–89) reported collecting material that resembled S. arctophila but which intergraded with S. arctica. These specimens need to be restudied. Representative specimens: Soper, J.D. 122106. Baffin Island, Panguirtung Fjord. 26 July 1924. CAN 46583; Wynne-Edwards, V.C. Baffin Island, Head of Clyde Inlet. 11 July 1950. CAN 283881; Polunin, N. 2376. Baffin Island, Cape Dorset. 15 June 1924. CAN 46516; Soper, J.D. 132178. Baffin Island, Head of Kinga Fjord. 31 July 1924. CAN 46520; Malte, M.O. s.n. Ellesmere Island, Craig Harbour. 2 Aug. 1927. CAN 46377; Malte, M.O. 118599. Ellesmere Island., Dundas Harbour. 27 July 1927. CAN 46381.
Salix arctophila × uva-ursi (Polunin 1940) There are four specimens in Canadian Museum of Nature that appears to be this hybrid. Specimens: M. O. Malte 118635, Baffin Island, Lake Harbour, 25–26 Aug 1927, CAN 46276 (undeveloped ovaries with patchy hairiness); Soper, J.D. 132144, Hekerton Islands, Cumberland Gulf. 29 July 1924, CAN 46176; A. P. Low 23039, Ungava, Erick Cove, 1 Aug. 1898, CAN; M. P. Porsild s.n. West Greenland, Fiskefjord, 29 July 1941. CAN. Some of these plants have the leaves of S. ura-ursi and the capsules of S. arctophila but others just look like depauperate specimens of S. arctophila. Skvortsov (1971) discounts this hybrid but notes that a few specimens are somewhat doubtful.
Salix arctophila × S. glauca. This hybrid is reported to be common in East Greenland but absent from West Greenland (Böcher 1952). It is not known to occur in Canada.
Illustrations. • Habit. Salix arctophila: plant growing with S. reticulata in lichen tundra. Some capsules have opened releasing seeds surrounded by hairs (fluff). Photograph taken at Richmond Gulf, Quebec, 19 July 1983. • Habit. Salix arctophila: habit, scale bar in cm. Photo taken at Iqaluit, Baffin Island, Nunavut, 30 August 1997. Voucher specimen: Susan Aiken and Cheryl McJannet, 97017, CAN. • Female flowering plants. Salix arctophila: female flowering plants. Leaves are shiny and glabrous. Ovaries are reddish. Photo taken at Richmond Gulf, Quebec, 17 July 1983. • Close-up of female catkin. Salix arctophila: Female catkins showing glabrous, glossy, elliptic leaves. Ovaries are often reddish and may appear to be glabrous. Photo taken at Richmond Gulf, Quebec, 19 July 1983. • Close-up of leaves. Salix arctophila: typically leaves are glabrous and the lower surface is glaucous with white wax. Photo taken at Iqaluit, Baffin Island, Nunavut, 30 Aug. 1997. Voucher specimen: Susan Aiken and Cheryl McJannet 97017, 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).
