Salix alaxensis (Andersson) Cov. var. alaxensis
Felt-leaf willow.
Salicaceae, willow family.
Proc. Wash. Acad. Sci. 2: 280. 1900.
Salix alaxensis var. obovalifolia Ball
Salix
speciosa var. alaxensis Anderss.
Vegetative morphology. Plants shrubs; mid shrubs, or tall shrubs, or trees; 100–400 cm high; not colonial. Aerial stems erect (rarely decumbent). Branches red-brown; not glaucous; hairy; villous; epidermis not flaky. Branchlets grey-brown, or red-brown; not glaucous (rarely glaucous); hairy; villous; hairs very dense; hairs spreading. Bud scale inner membrane fused to outer layer. Stipules present; leaf-like; apex acuminate, or acute. Petioles (3–)5–15(–20) mm long; glandular dots at the base of the leaf absent; convex to flat in cross-section; hairy; tomentose. Leaf blade bases acute, or cuneate. Juvenile leaves reddish, or yellowish green (often obscured); hairy; abaxial surface tomentose, or woolly (combined); hair very dense; hair white. Blades 50–110 mm long; 13–35 mm wide. Blades length-width ratio 2–4. Blades herbaceous, or leathery; oblong (broadly oblong), or elliptic (or narrowly elliptic), or obovate (to broadly obovate); revolute. Blades secondary veins impressed into adaxial surface, protruding on abaxial surface; arising along midrib. Blades adaxial surface dull; glabrous, or hairy. Blades adaxial surface hairs villous, or long-silky (floccose); sparse, or moderately dense; white and translucent, or grey. Blades abaxial surface hairy. Blades abaxial surface hairs very dense. Blades abaxial surface villous, or tomentose (combined). Blades abaxial surface hairs white, or translucent hairs; wavy; spreading, or erect. Blade margins glandular-dotted, or crenate; with submarginal glands; with teeth all around the blade (more towards tip); with teeth per cm 2–5 (3). Blade margins with glandular hairs all around leaf (more towards the tip). Leaf apices acuminate, or acute.
Reproductive morphology. Plants dioecious. Flowering stems present. Inflorescence a catkin. Catkins flowering before the opening of leaf buds; one to several catkins just below tip of previous year’s shoot. Male catkins densely flowered; 28–55 mm long; 13–20 mm wide; stout, or slender, or subglobose; peduncles 0 mm long; sessile; flowering branchlets 0 mm long. Female catkins densely flowered; 30–150 mm long; 10–22 mm wide; slender, or stout; peduncles 0–17 mm long; sessile; flowering branchlets 0 mm long. Floral bracts brown, or black; widest at middle, or widest at base; 1.5–2.5 mm long; hairy all over. Floral bracts hairs sparse; straight. Floral bracts entire. Perianth absent. Flowers unisexual. Stamens 2; filaments glabrous. Anthers purple becoming yellow; slender-cylindrical; axis straight; 0.6–0.9 mm long. Male flowers abaxial nectaries one; adaxial nectaries one; adaxial nectaries broad-rod, or slender-rod; adaxial nectaries 0.5–1 mm long. Female flowers adaxial nectaries absent; unlobed; slender-rod; 0.6–1 mm long; longer than stipes. Stipes 0–0.4 mm long. Ovaries pear-shaped; ovary gradually tapering to style; hairy; villous. Ovary hairs sparse, or moderately dense; white, or translucent; spreading; wavy; flattened (refractive). Styles 1.3–2.8 mm long. Stigmas slender-cylindrical; lobes 0.4–0.99–1.28 mm long. Ovules 12–18. Fruit a capsule. Fruit 4–5 mm long; glabrescent.
Chromosome information. 2n = 38. 38 (2x). - Böcher and Larsen (1950 Alaska); Zhukova (1967, 1969 north eastern Asia); Johnson and Packer (1968 northwestern Alaska); Suda and Argus (1969 Alaska, two counts); Löve and Löve (1982 arct Can); Petrovsky and Zhukova (1983 north eastern Asia). Ploidy levels recorded 2x.
Distribution. Northern hemisphere distribution: Canada, United States, Eurasia (northern and easternorthern Siberia). Arctic Islands: Banks, Victoria, Southampton.
Ecology and habitat. Habitats: Forming small thickets, 0.5–3 m tall, in protected places with good winter snow cover. On moderately well-drained to wet sand plains and remnant dune on river deltas, terraces, and river banks. Sometimes on coarse, calcareous gravel on river and lake shores or on scree slopes.
Notes. Salix alaxensis is characterized by leaves that are
bright green adaxially and densely white woolly abaxially. The branchlets are
also densely white villous-woolly. Petioles are often inflated around the large
floral buds. Flowering is precocious and the catkins are large and sessile. The
ovaries are hairy and the styles long.
This is one of the tallest growing
willows in the Arctic Archipelago. In the Masik River valley, south-western
Banks Island, it forms a dominating shrub tundra in association with S.
pulchra and S. richardsonii (Kuc 1970, 1974). It occurs in northern
Ungava (Maycock 1963) but evidently it has not been able to cross the Hudson
Straits to Baffin Island.
Illustrations. • Habit. Salix alaxensis: habit. Photo taken at Tuktoyaktuk, N.W.T., 14 Aug. 1997, by Laurie Consaul. • Habit. Salix alaxensis: plant habit growing as an erect shrub. In the Arctic it may grow as an erect shrub, up to 3 metres tall, in sheltered places. Photograph taken at Wakkpash Lake, British Columbia, 22 July 1977. • Habit. Salix alaxensis: plant growing as a low shrub, approximately 1 metre tall, in active sand dunes. The lower surface of the leaves are densely, white tomentose. Photograph taken at Meade River, Alaska, 15 July 1966. • Habitat. Salix alaxensis: Photo taken at Kitigazuit, N.W.T. by Laurie Consaul, Aug. and July 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1156 and 1157, CAN. • Tundra habitat. Salix alaxensis: plant growing in the tundra on stabilized sandy soil. Photograph taken at Meade River, Alaska, 14 July 1966. • Sand blowout habitat. Salix alaxensis: plants being buried by an active sand blowout. Photograph taken at Meade River, Alaska, 15 July 1966. • Close-up of female catkin. Salix alaxensis: Female catkin in fruit. Catkins are long and prominent, ranging from 30–150 mm long. The styles also are long. Photograph taken at Meade River, Alaska, 15 July 1966. • Close-up of leaves. Salix alaxensis: close-up of leaves showing densely villous-tomentose undersides and inflated petioles surrounding floral buds. Photo taken at Kitigazuit, N.W.T. by Laurie Consaul, Aug. and July 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1156, CAN. • Line drawing. Salix alaxensis: Line drawing. A. Male catkin. The catkin is sessile on the branch. B. Male flowers have 2 stamens, a floral bract with long, straight hairs and a single abaxial nectary. C. Female catkins. The catkin is sessile on the branch. D. Female flowers have a villous ovary, a long style, a long-hairy floral bract, and a single floral nectary that is longer than the stipe. E. Shoots bear leaves that are densely hairy beneath and have narrow leaf-like stipules at their base. • Arctic Island Distribution.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
