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mountain willow, Scouler willow, Scouler's willow

halberd 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. Plants 0.2–4 m. Stems: branches reddish brown, not glaucous, (slightly glossy), pilose; branchlets yellow-brown or red-brown, villous or pilose.
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 foliaceous, apex acute to acuminate;

petiole convex to flat, or shallowly grooved adaxially, 2–6(–9) mm, pilose or villous adaxially;

largest medial blade narrowly to broadly elliptic or narrowly ovate to ovate, 25–92 × 10–45 mm, 1.5–2.6(–3.4) times as long as wide, base convex, cuneate, or rounded, margins slightly revolute or flat, shallowly serrulate or entire, apex acuminate, acute, or convex, abaxial surface glaucous, sparsely pubescent, hairs wavy, adaxial dull to slightly glossy, pilose, sparsely pubescent or glabrous, midrib hairy, (hairs white and ferruginous);

proximal blade margins entire or finely serrulate;

juvenile blade sometimes reddish, sparsely pubescent abaxially, hairs white, sometimes also ferruginous.

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.

adaxial nectary oblong or square, 0.3–0.7 mm;

filaments distinct or basally connate, glabrous;

anthers purple turning yellow, 0.4–0.6 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 square or obovate, 0.3–0.6 mm, usually shorter than stipe;

stipe 0.4–1.2 mm;

ovary pyriform, glabrous, beak gradually tapering to styles;

ovules 12–22 per ovary;

styles connate (sometimes distinct 1/2 their lengths), 0.2–0.5 mm;

stigmas flat, abaxially non-papillate with rounded tip, or broadly cylindrical, or 2 plump lobes, 0.2–0.32–0.44 mm.

Capsules

4.5–11 mm.

3.2–8 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.

flowering as leaves emerge; staminate slender, stout, or subglobose, 14.5–34.5 × 8–12 mm, flowering branchlet 1–7 mm; pistillate moderately densely or loosely flowered, slender or stout, 21–59 × 6–16 mm, flowering branchlet 1.5–9 mm;

floral bract brown or bicolor, 1.2–1.8 mm, apex acute to rounded, abaxially glabrate to hairy, hairs straight to wavy.

2n

= 76.

= 38.

Salix scouleriana

Salix hastata

Phenology Flowering late Feb-mid Jun. Flowering early Jun-late Jul.
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 Sandy and gravelly river bars and floodplains, lakeshores, sand dunes and blowouts, Dryas tundra, alpine sedge meadows, balsam poplar thickets, openings in upland spruce-willow forests
Elevation 0-3500 m (0-11500 ft) 0-1200 m (0-3900 ft)
Distribution
from FNA
AK; AZ; CA; CO; ID; MT; NM; NV; OR; SD; UT; WA; WY; AB; BC; MB; NT; SK; YT; Mexico (Chihuahua, Sonora)
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; NT; YT; Eurasia (Norway, Russia, Siberia)
[BONAP county map]
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.)

Salix hastata is characterized by branches pilose with short, curved hairs; juvenile and mature leaves with white or ferruginous hairs adaxially, glaucous or not abaxially; and ovaries often reddish. See 61. S. barclayi and 64. S. farriae.

Subspecies subintegrifolia, characterized by entire or subentire leaf margins, is recognized in Flora Nordica as the major northern Eurasian race of Salix hastata, and is described as occurring across Russia into northwestern North America (B. Jonsell and T. Karlsson 2000+, vol. 1). Because leaf marginal toothing is highly variable throughout the species range (E. Hultén 1967), the subspecies is not recognized here or in Russia (A. K. Skvortsov 1999).

Hybrids:

Salix hastata forms natural hybrids with S. barclayi.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 7, p. 131. FNA vol. 7, p. 116.
Parent taxa Salicaceae > Salix > subg. Vetrix > sect. Cinerella Salicaceae > Salix > subg. Vetrix > sect. Hastatae
Sibling taxa
S. alaxensis, S. alba, S. amygdaloides, S. arbusculoides, S. arctica, S. arctophila, S. argyrocarpa, S. arizonica, S. athabascensis, S. atrocinerea, S. aurita, S. babylonica, S. ballii, S. barclayi, S. barrattiana, S. bebbiana, S. bonplandiana, S. boothii, S. brachycarpa, S. breweri, S. calcicola, S. candida, S. caprea, S. caroliniana, S. cascadensis, S. chamissonis, S. chlorolepis, S. cinerea, S. columbiana, S. commutata, S. cordata, S. daphnoides, S. delnortensis, S. discolor, S. drummondiana, S. eastwoodiae, S. elaeagnos, S. eriocephala, S. euxina, S. exigua, S. famelica, S. farriae, S. floridana, S. fuscescens, S. geyeriana, S. glauca, S. gooddingii, S. hastata, S. herbacea, S. hookeriana, S. humboldtiana, S. humilis, S. interior, S. irrorata, S. jejuna, S. jepsonii, S. laevigata, S. lasiandra, S. lasiolepis, S. lemmonii, S. ligulifolia, S. lucida, S. lutea, S. maccalliana, S. melanopsis, S. monochroma, S. monticola, S. myricoides, S. myrsinifolia, S. myrtillifolia, S. nigra, S. niphoclada, S. nivalis, S. nummularia, S. orestera, S. ovalifolia, S. pedicellaris, S. pellita, S. pentandra, S. petiolaris, S. petrophila, S. phlebophylla, S. planifolia, S. polaris, S. prolixa, S. pseudomonticola, S. pseudomyrsinites, S. pulchra, S. purpurea, S. pyrifolia, S. raupii, S. reticulata, S. richardsonii, S. rotundifolia, S. sericea, S. serissima, S. sessilifolia, S. setchelliana, S. silicicola, S. sitchensis, S. sphenophylla, S. stolonifera, S. taxifolia, S. thurberi, S. tracyi, S. triandra, S. turnorii, S. tweedyi, S. tyrrellii, S. uva-ursi, S. vestita, S. viminalis, S. wolfii, S. ×fragilis, S. ×jesupii, S. ×pendulina, S. ×sepulcralis, S. ×smithiana
S. alaxensis, S. alba, S. amygdaloides, S. arbusculoides, S. arctica, S. arctophila, S. argyrocarpa, S. arizonica, S. athabascensis, S. atrocinerea, S. aurita, S. babylonica, S. ballii, S. barclayi, S. barrattiana, S. bebbiana, S. bonplandiana, S. boothii, S. brachycarpa, S. breweri, S. calcicola, S. candida, S. caprea, S. caroliniana, S. cascadensis, S. chamissonis, S. chlorolepis, S. cinerea, S. columbiana, S. commutata, S. cordata, S. daphnoides, S. delnortensis, S. discolor, S. drummondiana, S. eastwoodiae, S. elaeagnos, S. eriocephala, S. euxina, S. exigua, S. famelica, S. farriae, S. floridana, S. fuscescens, S. geyeriana, S. glauca, S. gooddingii, S. herbacea, S. hookeriana, S. humboldtiana, S. humilis, S. interior, S. irrorata, S. jejuna, S. jepsonii, S. laevigata, S. lasiandra, S. lasiolepis, S. lemmonii, S. ligulifolia, S. lucida, S. lutea, S. maccalliana, S. melanopsis, S. monochroma, S. monticola, S. myricoides, S. myrsinifolia, S. myrtillifolia, S. nigra, S. niphoclada, S. nivalis, S. nummularia, S. orestera, S. ovalifolia, S. pedicellaris, S. pellita, S. pentandra, S. petiolaris, S. petrophila, S. phlebophylla, S. planifolia, S. polaris, S. prolixa, S. pseudomonticola, S. pseudomyrsinites, S. pulchra, S. purpurea, S. pyrifolia, S. raupii, S. reticulata, S. richardsonii, S. rotundifolia, S. scouleriana, S. sericea, S. serissima, S. sessilifolia, S. setchelliana, S. silicicola, S. sitchensis, S. sphenophylla, S. stolonifera, S. taxifolia, S. thurberi, S. tracyi, S. triandra, S. turnorii, S. tweedyi, S. tyrrellii, S. uva-ursi, S. vestita, S. viminalis, S. wolfii, S. ×fragilis, S. ×jesupii, S. ×pendulina, S. ×sepulcralis, S. ×smithiana
Synonyms S. scouleriana var. poikila S. farriae var. walpolei, S. hastata subsp. subintegrifolia, S. walpolei
Name authority Barratt ex Hooker: Fl. Bor.-Amer. 2: 145. (1838) Linnaeus: Sp. Pl. 2: 1017. (1753)
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