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little-tree willow, northern bush willow

Maccalla's willow, mccalla's willow

Stems

branches gray-brown to red-brown, not glaucous, glabrous;

branchlets red-brown, glabrous or puberulent.

branches dark red-brown, slightly or highly glossy, glabrous;

branchlets red-brown or yellow-brown, puberulent to glabrescent, hairs wavy, curved, straight, or geniculate.

Leaves

stipules rudimentary on early ones, apex acute;

petiole shallowly grooved adaxially, 3–11 mm, puberulent to glabrescent adaxially;

largest medial blade very narrowly elliptic to elliptic, 38–78 × 7–18 mm, base cuneate or convex, margins slightly revolute, serrulate, apex acuminate, acute, or convex, abaxial surface glaucous (sometimes obscured by hairs), sparsely to densely long-silky, hairs (white, sometimes also ferruginous), straight, adaxial highly or slightly glossy, glabrous;

proximal blade margins entire;

juvenile blade yellowish green, very densely long-silky abaxially, hairs white, sometimes also ferruginous.

stipules absent or rudimentary on early ones;

petiole convex to flat, or shallowly grooved adaxially, 4–15 mm, pilose or pubescent adaxially;

largest medial blade lorate or narrowly oblong, 40–85 × 8–25 mm, 2.9–4.8(–5.7) times as long as wide, base convex or cuneate, margins flat, entire, serrulate, or crenate, apex acute to sometimes acuminate, abaxial surface (pale), glabrous or sparsely pubescent, hairs white and ferruginous, straight, relatively short and stiff, adaxial highly glossy, glabrous, puberulent, or sparsely tomentose, hairs white and ferruginous;

proximal blade margins serrulate;

juvenile blade reddish.

Staminate flowers

adaxial nectary oblong, 0.6–0.9 mm;

filaments distinct;

anthers purple turning yellow, ellipsoid to globose, 0.3–0.6 mm.

abaxial nectary (0–)0.6–0.9 mm, adaxial nectary oblong or narrowly oblong, 0.5–1 mm, nectaries distinct or connate and cup-shaped;

filaments distinct, hairy on proximal 1/2;

anthers (purple turning yellow), ellipsoid or shortly cylindrical.

Pistillate flowers

adaxial nectary oblong or ovate, 0.6–1 mm;

ovary pyriform, beak gradually tapering to styles;

ovules 16–18 per ovary;

styles 0.3–0.5 mm.

(abaxial nectary present), adaxial nectary oblong, 0.4–1 mm, (nectaries distinct);

ovary pyriform;

ovules 12–16 per ovary;

styles connate or distinct 1/2 their lengths, 0.8–1.2 mm;

stigmas flat, abaxially non-papillate with rounded tip, or slenderly cylindrical, 0.3–0.6 mm.

Capsules

4–6 mm.

7–11 mm.

Catkins

flowering as or just before leaves emerge; staminate stout or slender, 17–43 × 5–10 mm, flowering branchlet 0–2.5 mm; pistillate densely to loosely flowered, stout to slender, 20–46 × 6–15 mm, flowering branchlet 0–6 mm;

floral bract tawny or brown, 0.8–1.2 mm, apex convex to rounded, abaxially hairy, hairs straight or wavy.

staminate (stout or subglobose), 15.5–42 × 9–16 mm, flowering branchlet 1.5–11 mm; pistillate densely flowered, slender, stout, or subglobose, 25–50 × 10–20 mm, flowering branchlet 3–12 mm;

floral bract 1.6–3.6 mm, apex rounded to truncate, entire, abaxially hairy throughout or proximally, hairs white and ferruginous, wavy.

2n

= 38.

= ca. 190, ca. 228.

Salix arbusculoides

Salix maccalliana

Phenology Flowering mid May-early Jul. Flowering early May-early Jul.
Habitat Stream margins, lakeshores, openings in white spruce forests, treed bogs, sedge fens, edges of alpine and arctic tundra Sedge meadows, shrubby fens, marly or bouldery lakeshores, string bogs, treed bogs, Calamagrostis grasslands
Elevation 0-2000 m (0-6600 ft) 0-1500 m (0-4900 ft)
Distribution
from FNA
AK; AB; BC; MB; NT; NU; ON; QC; SK; YT
[BONAP county map]
from FNA
MN; ND; WA; AB; BC; MB; NT; ON; QC; SK; YT
[WildflowerSearch map]
[BONAP county map]
Discussion

Glands on leaf teeth of Salix arbusculoides are sometimes covered with fine crystals of sulphur, calcium, potassium, and silicon (R. Cooper, pers. comm.), indicating that they can function as hydathodes as well as resin glands.

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

The decaploid to dodecaploid chromosome number for Salix maccalliana, highest in the genus, suggests a complex origin. Relationships with subg. Chamaetia and subg. Salix were suggested by Rowlee and by H. M. Raup (1959). Staminate flowers with abaxial nectaries, tawny and persistent bracts, and villous ovaries suggest a link with S. glauca; leaves with coarse, ferruginous hairs and serrate margins suggest S. lucida (Rowlee). Although S. maccalliana is phenetically closer to sect. Salicaster than to (subg. Chamaetia) sect. Glaucae (G. W. Argus 1997), it is probable that because it incorporates genomes from more than one subgenus, its subgeneric placement is arbitrary.

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

Source FNA vol. 7, p. 141. FNA vol. 7, p. 49.
Parent taxa Salicaceae > Salix > subg. Vetrix > sect. Arbuscella Salicaceae > Salix > subg. Salix > sect. Maccallianae
Sibling taxa
S. alaxensis, S. alba, S. amygdaloides, 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. 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. 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
Name authority Andersson: Monogr. Salicum, 147, plate 8, fig. 81. (1867) Rowlee: Bull. Torrey Bot. Club 34: 158. (1907)
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