The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

halberd willow

Idaho willow, wolf willow, Wolf's willow

Habit Plants 0.2–4 m. Stems: branches reddish brown, not glaucous, (slightly glossy), pilose; branchlets yellow-brown or red-brown, villous or pilose. Plants 0.1–2 m. Stems: branches red-brown, violet, yellow-gray, or yellow-brown, pubescent or pilose to glabrescent; branchlets yellowish, yellow-brown, red-brown, or yellow-green, sparsely or moderately densely pubescent, or densely long-silky, (inner membranaceous bud-scale layer free, separating from outer layer).
Leaves

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.

stipules rudimentary or foliaceous on early ones, foliaceous on late ones, apex rounded, acuminate, or acute;

petiole convex to flat, or shallowly grooved adaxially, 3–12 mm, pubescent, long-silky, or villous adaxially;

largest medial blade narrowly oblong, narrowly elliptic, elliptic, or oblanceolate, 26–56 × 8–16.5 mm, 2.5–3.7–5.6 times as long as wide, base cuneate, convex, or rounded, margins flat, entire, apex acute, acuminate, or convex, abaxial surface not glaucous, pubescent, short-silky, or villous, hairs appressed or spreading, straight or wavy, adaxial dull, sparsely to densely silky or villous;

proximal blade margins entire;

juvenile blade yellowish green, densely short- or long-silky or villous abaxially, hairs white.

Staminate flowers

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.

(abaxial nectary 0–0.2 mm), adaxial nectary oblong, 0.4–1.1 mm, (nectaries distinct);

filaments distinct, glabrous;

anthers yellow, 0.3–0.5 mm.

Pistillate flowers

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.

adaxial nectary oblong, ovate, or flask-shaped, 0.4–1.1 mm, shorter to longer than stipe;

stipe 0.2–0.9 mm;

ovary pyriform, glabrous or hairy, beak gradually tapering to or slightly bulged below styles;

ovules 8–16 per ovary;

styles 0.3–1 mm;

stigmas flat, abaxially non-papillate with rounded or pointed tip, or slenderly or broadly cylindrical, 0.24–0.3–0.4 mm.

Capsules

3.2–8 mm.

3–5 mm.

Catkins

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.

flowering as leaves emerge; staminate stout or subglobose, 9.5–16 × 6–12 mm, flowering branchlet 1–5.5 mm; pistillate moderately or very densely flowered, stout, subglobose or globose, 8.5–38 × 5–12 mm, flowering branchlet 1–11 mm;

floral bract brown, black, or bicolor, 0.8–2 mm, apex rounded or acute, abaxially hairy, hairs wavy, straight, or curly.

2n

= 38.

Salix hastata

Salix wolfii

Phenology Flowering early Jun-late Jul.
Habitat 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 0-1200 m (0-3900 ft)
Distribution
from FNA
AK; NT; YT; Eurasia (Norway, Russia, Siberia)
[BONAP county map]
from FNA
CO; ID; MT; NV; OR; UT; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

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.)

Varieties 2 (2 in the flora).

The two varieties of Salix wolfii are distinguished mainly by ovary hairiness; other characters in the key overlap. Ovaries of the typical var. wolfii are glabrous and those of var. idahoensis are hairy. In the latter variety, ovaries are sometimes hairy throughout, but most have hairs in streaks or in a patch at the base of the ovary and on the stipes. These plants usually do not set seed and may be infertile hybrids. Occasional occurrence of staminate flowers with abaxial nectaries suggests that this variety may be a hybrid with S. glauca or S. brachycarpa, although it could also be with S. eastwoodiae, as suggested by S. J. Brunsfeld and F. D. Johnson (1985). The presence of both abaxial and adaxial nectaries in staminate flowers of S. wolfii (staminate plants cannot be identified to variety) is an unusual character in subg. Vetrix; it rarely occurs in S. argyrocarpa, S. breweri, and S. orestera, but is common in S. wolfii. Both hairy ovaries and abaxial nectaries could have been acquired through hybridization and introgression, or polyploidy, with S. glauca or S. brachycarpa. Cytological study of S. wolfii may help answer this question.

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

Key
1. Ovaries glabrous; pistillate adaxial nectaries 0.4-0.8 mm; stipes 0.2-0.9 mm.
var. wolfii
1. Ovaries pubescent or tomentose (hairs in streaks or patches); pistillate adaxial nectaries 0.4-1.1 mm; stipes 0-0.4 mm
var. idahoensis
Source FNA vol. 7, p. 116. FNA vol. 7, p. 107.
Parent taxa Salicaceae > Salix > subg. Vetrix > sect. Hastatae 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. 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
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. 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. ×fragilis, S. ×jesupii, S. ×pendulina, S. ×sepulcralis, S. ×smithiana
Subordinate taxa
S. wolfii var. idahoensis, S. wolfii var. wolfii
Synonyms S. farriae var. walpolei, S. hastata subsp. subintegrifolia, S. walpolei
Name authority Linnaeus: Sp. Pl. 2: 1017. (1753) Bebb: in J. T. Rothrock, Rep. U. S. Geogr. Surv., Wheeler, 241. (1879)
Web links