Salix scouleriana |
Salix euxina |
|
---|---|---|
mountain willow, Scouler willow, Scouler's willow |
brittle willow, crack willow |
|
Habit | Shrubs or trees, 1–10(–20) m. Stems: branches gray-brown, yellow-brown, or red-brown, not glaucous, glabrous or tomentose; branchlets yellow-green or yellow-brown, sparsely to densely villous, tomentose, or velvety. | Trees, 6–18 m. Stems: branches highly brittle at base, yellow-green, yellow-brown, or gray-brown, (highly glossy), glabrous; branchlets yellow-green, yellow-brown, or red-brown, (highly glossy), glabrous. |
Leaves | stipules absent, rudimentary, or foliaceous on early ones, foliaceous on late ones, (1–16 mm), apex acute or acuminate; petiole convex to flat adaxially, 2–13 mm, velvety or villous adaxially; largest medial blade usually oblanceolate, sometimes narrowly elliptic, elliptic or obovate, 29–100 × 9–37 mm, 1.7–3.9 times as long as wide, base cuneate or convex, margins strongly to slightly revolute or flat, entire, remotely serrate, crenate, or sinuate, (glands submarginal or epilaminal), apex acuminate, convex, or rounded, abaxial surface glaucous, sparsely to densely short- to long-silky or woolly, hairs (white, sometimes also ferruginous), wavy or straight, adaxial slightly glossy, pilose or moderately densely short-silky, midrib velutinous or villous, (hairs white, sometimes also ferruginous); proximal blade margins entire, serrulate, or crenulate; juvenile blade reddish or yellowish green, sparsely to densely villous, short- or long-silky abaxially, hairs white, sometimes also ferruginous. |
stipules rudimentary on early ones, rudimentary or foliaceous on late ones, (early deciduous to marcescent), apex acuminate or acute; petiole deeply grooved adaxially (margins usually touching), 6–8.6 mm, with pairs of spherical glands distally, glabrous or puberulent adaxially; largest medial blade hemiamphistomatous or hypostomatous, lanceolate, narrowly oblong, or narrowly elliptic, 60–120 × 14–30 mm, 3.6–6.5 times as long as wide, base convex or rounded, margins flat or slightly revolute, serrate, crenate, or crenulate, apex acute, acuminate, or caudate, abaxial surface (not glaucous), glabrous, adaxial slightly or highly glossy, glabrous; proximal blade margins entire; juvenile blade yellowish green or reddish, glabrous. |
Staminate flowers | adaxial nectary oblong or square, 0.4–0.9 mm; filaments distinct, glabrous or hairy on proximal 1/2; anthers purple turning yellow, ellipsoid to shortly cylindrical, 0.7–1.2 mm. |
abaxial nectary present, adaxial nectary oblong, 0.3–0.6 mm, nectaries distinct; filaments distinct or connate less than 1/2 their lengths, hairy at base; anthers ellipsoid, 0.4–0.5 mm. |
Pistillate flowers | adaxial nectary oblong or square, 0.2–0.8 mm, shorter than stipe; stipe 0.8–2.3 mm; ovary pyriform or obclavate, densely long-silky, beak slightly bulged below styles; ovules 10–18 per ovary; styles 0.2–0.6 mm; stigmas slenderly cylindrical, 0.4–0.82–1.04 mm. |
adaxial nectary oblong or square, 0.3–0.6 mm, shorter than stipe; stipe 0.6–1.2 mm; ovary pyriform, beak gradually tapering to styles; styles connate, 0.3–0.5 mm; stigmas flat, abaxially non-papillate with rounded tip, or 2 plump lobes, 0.3–0.5 mm. |
Capsules | 4.5–11 mm. |
3–5 mm. |
Catkins | flowering before leaves emerge; staminate stout or subglobose, 18–40.5 × 8–22 mm, flowering branchlet 0–4 mm; pistillate very densely flowered, slender or stout, 18–60(–90 in fruit) × 10–22 mm, flowering branchlet 0–8 mm; floral bract brown, black, or bicolor, 1.5–4.5 mm, apex rounded or acute, abaxially hairy, hairs straight. |
staminate 24–40 × 7–15 mm, flowering branchlet 12–15 mm; pistillate moderately densely flowered, stout, 24–35 mm, flowering branchlet 12–15 mm; floral bract (greenish or tawny), 0.8–1.3 mm, apex convex or rounded, entire or erose, abaxially hairy, hairs straight or wavy. |
2n | = 76. |
= 76. |
Salix scouleriana |
Salix euxina |
|
Phenology | Flowering late Feb-mid Jun. | Flowering late spring. |
Habitat | Dry conifer forests, mature woods on edges of streams and lakes, treed bogs, meadows, subalpine slopes, springs, pine barrens, openings in old burns, arroyos and disturbed sites, sandy, silty-clay, or gravelly, igneous substrates | Cultivated or riparian |
Elevation | 0-3500 m (0-11500 ft) | |
Distribution |
AK; AZ; CA; CO; ID; MT; NM; NV; OR; SD; UT; WA; WY; AB; BC; MB; NT; SK; YT; Mexico (Chihuahua, Sonora)
|
ON; QC; n Asia; nw Asia [Introduced in North America; introduced also in Europe] |
Discussion | Western Salix scouleriana and eastern S. humilis are closely related and are sometimes difficult to separate. Although there is an apparent range disjunction between them in western Manitoba, it may be a collecting gap. In general, S. scouleriana differs from S. humilis in being a taller shrub, sometimes even tree-like, with broader leaves and longer catkins, floral bracts, stigmas, and styles, but these quantitative characteristics all overlap. The apparent difference in anther length (S. scouleriana 0.7–1.2 mm; S. humilis 0.4–0.6 mm) may be correlated with a difference in chromosome number. Salix scouleriana is tetraploid (Y. Suda and G. W. Argus 1968); S. humilis has been reported to be both diploid (Suda and Argus; L. Zsuffa and Y. Raj, unpubl.) and tetraploid (R. D. Dorn 1976). The latter count was from the same population as the one by Suda and Argus. Further chromosome counts are indicated. See 77. Salix hookeriana for comparative descriptions. Hybrids: Salix scouleriana forms natural hybrids with S. hookeriana, S. planifolia, and S. pulchra. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Distribution of Salix euxina (formerly S. fragilis) in the flora area is uncertain. It may occur throughout southern Canada and the United States; often known as the cultivar “Bullata,” it rarely escapes. Salix euxina is native to the northern Black Sea and the Transcaucausian regions. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 131. | FNA vol. 7, p. 43. |
Parent taxa | Salicaceae > Salix > subg. Vetrix > sect. Cinerella | Salicaceae > Salix > subg. Salix > sect. Salix |
Sibling taxa | ||
Synonyms | S. scouleriana var. poikila | S. fragilis var. sphaerica |
Name authority | Barratt ex Hooker: Fl. Bor.-Amer. 2: 145. (1838) | I. V. Belyaeva: Taxon 58: 1345. (2009) |
Web links |
|