Salix glauca L. var. acutifolia (Hook.) C. Schneider
Gray-leaf willow.
Bot. Gaz. 66: 327. 1918.
Salix glauca subsp. acutifolia (Hook.) Hultén
Salix glauca var. alicea Ball
Salix glauca var. perstipulata Raup
Salix glauca var. poliophylla (Schneid.) Raup
Salix glauca var. seemanii (Rydb.) Ostenf.
Salix seemanii Rydb.
Salix villosa var. acutifolia Hook.
Plants low shrubs, or mid shrubs, or tall shrubs; more than 15 cm high; 25–60 cm high; not colonial. Stems. Aerial stems erect. Branches red-brown, or brownish; not glaucous; glabrous, or hairy, or glabrescent; villous, or pilose; epidermis flaky. Branchlets red-brown, or brownish; not glaucous; glabrous, or hairy; villous; hairs moderately dense, or very dense, or sparse; hairs appressed. Bud scale inner membrane free but not separating from outer membrane. Stipules. Stipules present (linear to lanceolate); leaf-like; apex acuminate. Petioles. Petioles 4–27 mm long; glandular dots at the base of the leaf absent; deeply concave in cross-section, but margins not covering the groove, or shallowly concave in cross-section; hairy. Petioles adaxial surface pilose. Leaves. Juvenile leaves yellowish green; hairy; abaxial surface villous, or hairs long-silky; hair very dense, or moderately dense; hair white. Blades 4.3–8.2 cm long; 12–39 mm wide; length-width ratio 2.2–4.8; herbaceous, or leathery; oblanceolate, or obovate, or elliptic (to broadly elliptic); revolute, or flat; secondary veins impressed into adaxial surface, protruding on abaxial surface, or flat on adaxial surface, protruding on abaxial surface; secondary veins arising along midrib; stomata only on abaxial surface. Blades adaxial surface shiny; glabrous, or hairy, or glabrescent; hairs pilose; hairs sparse; hairs white and translucent. Blades abaxial surface hairy; glaucous; villous, tomentose (villous-tomentose), hairs short-silky; hairs sparse, or moderately dense, or very dense; hairs white, or translucent; hairs spreading, or appressed; hairs straight, or wavy, or curved. Leaf bases acute, or attenuate. Leaf margins entire and glandular-dotted; with teeth per cm 2–5; with submarginal glands. Leaf margins with glandular hairs all around leaf. Leaf apices acuminate, 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; 17–44 mm long; 9–17 mm wide; slender, or stout; peduncles 2–5 mm long; borne on a flowering branchlet; flowering branchlets 2–9 mm long. Female catkins. Female catkins densely flowered, or moderately densely flowered (loose at base); 20–80 mm long; 8–17 mm wide; slender, or stout; peduncles 3–19 mm long; borne on a flowering branchlet; flowering branchlets 6–40 mm long. Floral bracts. Floral bracts tawny, or bicolour, or brown (light); widest at middle; 1.5–2.5 mm long; hairy all over; hairs moderately dense; hairs wavy; entire. Stamens 2; filaments glabrous. Anthers purple becoming yellow; ellipsoid, or stout-cylindrical; axis straight; 0.5–0.8 mm long. Male flowers. Male flowers abaxial nectaries absent, or one (sometimes not evident); adaxial nectaries one; adaxial nectaries slender-rod, or broad-rod, or square; adaxial nectaries 0.6–0.9 mm long; adaxial nectaries separate. Female flowers. Female flowers adaxial nectaries absent; unlobed; slender-rod, or broad-rod; 0.6–1.4 mm long; shorter than stipes, or equal to stipes (rarely longer). Stipes 0.5–2.8 mm long. Ovaries pear-shaped, or inverse club-shaped; ovary gradually tapering to style; hairy; ovary tomentose, or hairs short-silky, or pubescent. Ovary hair moderately dense, or dense; white, or translucent; spreading, or appressed; straight, or wavy; flattened. Styles 0.3–1.4 mm long. Stigmas slender-cylindrical; lobes 0.4–0.59–0.8 mm long. Ovules 12–22. Fruit. Fruit 5–9 mm long; glabrescent.
Chromosome inforamtion. 2n = 76, 95, and 114. 4x Suda & Argus 1969. 5x Suda & Argus 1969. 6x Suda & Argus 1969. Ploidy levels recorded 4, 5, & 6x.
Distribution. Northern hemisphere: Canada, United States, Eurasia (eastern Russia). Canada: B.C., Yukon, N.W.T., Nunavut. USA: Alaska.
Ecology and habitat. Rare in our area. Forming low thickets in disturbed calcareous gravel.
Notes. Salix glauca var. acutifolia is an erect shrub. Its leaves are glaucous abaxially and moderately to very densely hairy abaxially and sparsely hairy to glabrate adaxially, stipules are usually prominent, 4–17 mm long; catkins are densely flowered and borne on a leafy flowering branchlet. Its floral bracts are pale and the ovaries are densely hairy.
A population of S. glauca var. acutifolia was found by G. Argus and S. Edlund on Victoria Island, in a gravel deposit disturbed by heavy equipment, about 1.5 km NNW of the Dew Line station. It was growing with Salix richardsonii and S. arctica. They also collected a single plant in a disturbed area adjacent to the road on the northeast side of the Dew Line station. On Victoria Island it is known only from these two disturbed habitats. The first population included both pistillate and staminate specimens and is presumed to be a natural occurrence. It is native to Banks Island and the mainland south of Victoria Island so its occurrence on Victoria is not unreasonable. It was collected earlier by Thannheiser, as S. glauca subsp. callicarpaea (Thannheiser, unpublished), but the specimen was revised by Argus to S. glauca var. acutifolia.
Hybrids
Salix glauca var. acutifolia × S. niphoclada. This putative hybrid recombines the characteristics of the parental species. Of this hybrid Argus (1965) wrote, ‘Characteristics indicative of [S. niphoclada] are the short petioles, small narrowly elliptic-oblanceolate leaves with acute-attenuate apices, small stipules, and narrow, loosely flowered aments [catkins]. Characteristics suggesting S. glauca are the long petioles, large oblanceolate leaves, large stipules, and densely flowered, broadly cylindrical aments.’.
Illustrations. • Habit. Salix glauca var. acutifolia: habit. Photo taken at Kitigazuit, N.W.T. by Laurie Consaul, Aug. 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1158, CAN. • Habitat. Salix glauca var. acutifolia: habitat. Photo taken at Kitigazuit, N.W.T. by Laurie Consaul, 17 Aug. 1997. • Close-up of plant. Salix glauca var. acutifolia: close-up of plant. Photo taken at Kitigazuit, N.W.T. by Laurie Consaul, Aug. 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1158, CAN. • Close-up of two female catkins. Salix glauca var. acutifolia: close-up of two female catkins. Photo taken at the Kitigazuit, N.W.T. by Laurie Consaul, Aug. & July 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1158, CAN. • Close-up of female catkin. Salix glauca var. acutifolia: close-up of female catkin. Photo taken at Kitigazuit, N.W.T. by Laurie Consaul, Aug. & July 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1158, CAN. • Line drawing. Salix glauca var. acutifolia: A. Branch with male catkins and a young leafy shoot. Male catkins are borne on short, leafy flowering branchlets. B. Female catkins are borne on a leafy flowering branchlet. The leaves are narrowly elliptic with slender leaf-like stipules. • 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).
