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

basket willow, common osier, osier, osier willow, silky osier

Idaho willow, wolf willow, Wolf's willow

Habit Plants 0.1–2 m.
Stems

branches yellow-brown, gray-brown, or yellowish, not glaucous, glabrous or puberulent;

branchlets yellow-brown or yellowish (sometimes color obscured by hairs), glabrous, densely to sparsely villous, velvety, or puberulent.

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 (not adnate to petioles), rudimentary or absent on early ones, (late ones sometimes brownish, linear, 5.4–10.4 mm), apex acuminate;

petiole shallowly grooved adaxially, 4–13 mm, villous, puberulent, or velvety adaxially;

largest medial blade linear, lorate, narrowly oblong, or narrowly elliptic, 53–130 × 5–33 mm, base cuneate, margins strongly revolute, sinuate or apparently entire, (glands epilaminal), apex acuminate, acute, or convex, abaxial surface apparently glaucous (obscured by hairs), densely short-silky, woolly, or tomentose, (midribs prominent, yellowish, and hairy), hairs appressed, spreading or erect, straight or wavy, adaxial dull or slightly glossy, sparsely or moderately densely pubescent, hairs gray;

proximal blade margins entire;

juvenile blade yellowish green, very densely tomentose or short-silky abaxially, hairs white.

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 narrowly oblong or oblong, 0.6–1.5 mm;

filaments distinct;

anthers purple turning yellow, ellipsoid to shortly cylindrical, 0.6–0.8 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 narrowly oblong or oblong, 0.9–1.4 mm;

ovary pyriform, beak gradually tapering to styles;

ovules 12–18 per ovary;

styles 0.6–1.8 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

4–6 mm.

3–5 mm.

Catkins

flowering just before or as leaves emerge; staminate stout, 24–48 mm, flowering branchlet 0–2 mm; pistillate densely flowered, 23–55 mm, flowering branchlet 0–6 mm;

floral bract brown or tawny, 1.6–2.2 mm, apex convex or rounded, abaxially hairy, hairs straight.

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 viminalis

Salix wolfii

Phenology Flowering Apr-early May.
Habitat Sandy, open woods, cobble rivershores, lake margins, and roadsides
Elevation 0-300 m (0-1000 ft)
Distribution
from FNA
CT; IA; IN; MA; ME; NJ; NY; OH; RI; VT; NB; NF; NS; ON; PE; QC; Europe [Introduced in North America]
[BONAP county map]
from FNA
CO; ID; MT; NV; OR; UT; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Salix ×smithiana (S. caprea × S. viminalis) is distinguished from S. viminalis by having leaf blades usually broad, 2.8–4.9(–6.4) times as long as wide, stipes 0.9–2 mm, ovaries short-silky, branches ± brittle at base, and petioles flat to convex adaxially; S. viminalis has leaf blades usually very narrow, 4.7–13.7 times as long as wide, stipes 0.1–0.5 mm, ovaries long-silky, branches flexible at base, and petioles shallowly grooved adaxially.

See Salix ×smithiana [p. 132] and 86. S. pellita for further comparative descriptions.

(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. 149. FNA vol. 7, p. 107.
Parent taxa Salicaceae > Salix > subg. Vetrix > sect. Viminella 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. 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. 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
Name authority Linnaeus: Sp. Pl. 2: 1021. (1753) Bebb: in J. T. Rothrock, Rep. U. S. Geogr. Surv., Wheeler, 241. (1879)
Web links