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balsam willow

Booth's willow

Habit Plants 0.4–4 m. Stems: branches red-brown, not glaucous, (highly glossy), glabrous; branchlets red-brown, yellow-brown, or yellowish, (not or weakly glaucous), glabrous, (inner membranaceous bud-scale layer free, not separating from outer layer). Plants 0.3–6 m. Stems: branches yellow-gray, yellow-brown, or red-brown, not glaucous, glabrous, pilose, or villous; branchlets yellow-brown, gray-brown, or red-brown, (not or weakly glaucous), glabrous, pilose, or moderately densely villous.
Leaves

stipules (early deciduous), foliaceous or rudimentary on early ones, foliaceous on late ones, apex acute, convex, or rounded;

petiole convex to flat, or shallowly grooved adaxially, 7–20 mm, glabrous or sparsely velvety adaxially;

largest medial blade narrowly oblong, oblong, elliptic, or broadly elliptic, 30–103 × 19–40 mm, 1.5–3.4 times as long as wide, base cordate, subcordate, rounded or convex, margins flat or slightly revolute, serrulate, irregularly serrate, crenate, or sinuate, apex acute or acuminate, abaxial surface glaucous, glabrous, adaxial slightly or highly glossy, glabrous;

proximal blade margins serrulate or entire;

juvenile blade translucent, glabrous or pilose abaxially, hairs white.

stipules foliaceous, apex acute, acuminate, or rounded;

petiole convex to flat, or shallowly grooved adaxially, 3–17 mm, pilose, villous, or pubescent adaxially;

largest medial blade (often amphistomatous), lorate, narrowly oblong, or narrowly to broadly elliptic, 26–102 × 8–30 mm, 2.5–3–5.2 times as long as wide, base convex, rounded, or subcordate, margins flat or slightly revolute, (thickened), entire or serrulate, apex acute or acuminate, abaxial surface not glaucous, glabrous, pilose, or moderately densely short-silky, hairs (white, sometimes also ferruginous), wavy, adaxial dull or slightly glossy, glabrous or moderately densely pilose;

proximal blade margins entire, crenate, or serrulate;

juvenile blade green, pilose to densely villous abaxially, hairs white, sometimes also ferruginous.

Staminate flowers

adaxial nectary square or ovate, 0.3–0.5 mm;

filaments distinct, glabrous or sparsely hairy basally;

anthers yellow, (ellipsoid or shortly cylindrical), 0.5–0.8 mm.

adaxial nectary narrowly oblong, oblong, ovate, or flask-shaped, 0.6–1.5 mm;

filaments distinct or connate ca. 1/2 their lengths, glabrous, hairy on proximal 1/2;

anthers yellow or purple turning yellow, 0.5–0.8 mm.

Pistillate flowers

adaxial nectary narrowly ovate or square, 0.3–0.7 mm, shorter than stipe;

stipe 1.8–3.5 mm;

ovary obclavate, glabrous, beak slightly bulged below styles;

ovules 10–19 per ovary;

styles 0.4–0.5 mm;

stigmas flat, abaxially non-papillate with rounded tip, or 2 plump lobes, 0.2–0.23–0.32 mm.

adaxial nectary oblong, ovate, or flask-shaped, 0.3–0.8 mm, shorter than stipe;

stipe 0.5–2.5 mm;

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

ovules 10–18 per ovary;

styles 0.3–1.4 mm;

stigmas flat, abaxially non-papillate with rounded tip, or slenderly cylindrical, or 2 plump lobes, 0.2–0.26–0.48 mm.

Capsules

7–8 mm.

2.5–6 mm.

Catkins

staminate flowering just before leaves emerge, pistillate flowering as leaves emerge; staminate stout or slender, 18.5–63 × 7–15 mm, flowering branchlet 1–5 mm; pistillate loosely flowered, stout or slender, 25–85 × 8–20 mm, flowering branchlet 2–22 mm;

floral bract tawny, 1–2.4 mm, apex acute or convex, abaxially sparsely to moderately densely hairy, hairs straight or wavy.

flowering as or just before leaves emerge; staminate stout or subglobose, 7–37 × 5–12 mm, flowering branchlet 0.5–5.6 mm; pistillate densely or moderately densely flowered, stout, 12–62 × 7–17 mm, flowering branchlet 1–9 mm;

floral bract brown, 0.7–2.1 mm, apex rounded or retuse, abaxially hairy throughout or proximally, hairs straight, wavy, or curly.

2n

= 38.

= 76.

Salix pyrifolia

Salix boothii

Phenology Flowering May-mid Jun(-mid Jul in subalpine). Flowering early Apr-early Jul.
Habitat Fens, wet lake and slough margins, treed bogs Wet subalpine meadows, seepages, streams, lakeshores
Elevation 0-300 m (-1600 m in subalpine) (0-1000 ft (-5200 ft in subalpine)) 1500-3200 m (4900-10500 ft)
Distribution
from FNA
ME; MI; MN; NH; NY; VT; WI; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC; SK
[WildflowerSearch map]
[BONAP county map]
Discussion

Salix pyrifolia is characterized by juvenile leaves membranaceous and translucent, and largest medial leaves subcoriaceous, with abaxial surfaces reticulate, and with bases often cordate. Buds and foliage are reported to have a balsam-like fragrance.

Hybrids:

Salix pyrifolia forms natural hybrids with S. brachycarpa var. psammophila. Hybrids with S. discolor have been reported (C. K. Schneider 1921; M. L. Fernald 1950) but no convincing specimens have been seen.

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

Hybrids:

Salix boothii forms natural hybrids with S. brachycarpa var. brachycarpa, S. eastwoodiae, S. glauca var. villosa, and S. wolfii. There are numerous intermediate specimens of S. boothii that suggest hybridization with S. arizonica, S. brachycarpa, S. eastwoodiae, S. lutea, or S. wolfii, but further study is needed. A DNA study of S. arizonica showed that a specimen from southwestern Utah previously identified as S. arizonica × S. wolfii probably was S. boothii × S. wolfii (J. T. Thompson et al. 2003).

In Mountain Park, Alberta, and the Steens Mountains, Oregon, the putative hybrid Salix boothii × S. glauca var. villosa grew in thickets with both parents. Ovaries were sparsely hairy on the distal half or on the beak, leaves were glaucous abaxially, and floral bracts were mostly glabrous abaxially, but some with hairs proximally. One plant in fruit produced copious seed hairs but no seed.

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

Source FNA vol. 7, p. 115. FNA vol. 7, p. 113.
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. 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. 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. 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. wolfii, S. ×fragilis, S. ×jesupii, S. ×pendulina, S. ×sepulcralis, S. ×smithiana
Synonyms S. balsamifera, S. pyrifolia var. lanceolata S. novae-angliae var. aequalis, S. pseudocordata var. aequalis
Name authority Andersson: Monogr. Salicum, 162, plate 8, fig. 93. (1867) Dorn: Canad. J. Bot. 53: 1505. (1975)
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