Salix alaxensis (Andersson) Cov. var. alaxensis
Felt-leaf willow.
Proc. Wash. Acad. Sci. 2: 280. 1900.
Salix alaxensis var. obovalifolia Ball
Salix speciosa var. alaxensis Anderss.
Plants mid shrubs, or tall shrubs, or trees; more than 15 cm high; 100–400 cm high; not colonial. Stems. Aerial stems erect (rarely decumbent). Branches red-brown; not glaucous; hairy; villous; epidermis not flaky. Branchlets gray-brown, or red-brown; not glaucous (rarely glaucous); hairy; villous; hairs very dense; hairs spreading. Bud scale inner membrane fused to outer layer. Stipules. Stipules present; leaf-like; apex acuminate, or acute. Petioles. Petioles (3–)5–15(–20) mm long; glandular dots at the base of the leaf absent; convex to flat in cross-section; hairy. Petioles adaxial surface tomentose. Leaves. Juvenile leaves reddish, or yellowish green (often obscured); hairy; abaxial surface tomentose, or woolly (combined); hair very dense; hair white. Blades 5–11 cm long; 13–35 mm wide; length-width ratio 2–4; herbaceous, or leathery; oblong (broadly oblong), or elliptic (or narrowly elliptic), or obovate (to broadly obovate); revolute; secondary veins impressed into adaxial surface, protruding on abaxial surface; secondary veins arising along midrib; stomata only on abaxial surface. Blades adaxial surface dull; glabrous, or hairy; hairs villous, or long-silky (floccose); hairs sparse, or moderately dense; hairs white and translucent, or gray. Blades abaxial surface hairy; obscured by hairs; villous, tomentose (combined); hairs very dense; hairs white, or translucent; hairs spreading, or erect; hairs wavy. Leaf bases acute, or cuneate. Leaf margins glandular-dotted, or crenate; with teeth all around leaf (more towards tip); with teeth per cm 2–5 (3); with submarginal glands. Leaf margins with glandular hairs all around leaf (more towards the tip). Leaf apices acuminate, or acute.
Plants dioecious. Catkins. Catkins flowering before the opening of leaf buds; one to several catkins just below tip of previous year’s shoot. Male catkins. 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. 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. Floral bracts brown, or black; widest at middle, or widest at base; 1.5–2.5 mm long; hairy all over; hairs sparse; hairs straight; entire. Stamens 2; filaments glabrous. Anthers purple becoming yellow; slender-cylindrical; axis straight; 0.6–0.9 mm long. Male flowers. Male flowers abaxial nectaries one; adaxial nectaries one; adaxial nectaries broad-rod, or slender-rod; adaxial nectaries 0.5–1 mm long. Female flowers. 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; ovary villous. Ovary hair 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. Fruit 4–5 mm long; glabrescent.
Chromosome inforamtion. 2n = 38. Johnson & Packer 1968; Löve & Löve 1982; Suda & Argus 1969. Russia, Zhukova 1967, 1969. Ploidy levels recorded 2x.
Distribution. Northern hemisphere: Canada, United States, Eurasia (northern and eastern Siberia). Canada: Alta., B.C., Man., Que., Yukon, N.W.T., Nunavut. USA: Alaska.
Ecology and habitat. 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, southwestern 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. & July 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1156 & 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. & 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: 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).
