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black willow

skeleton-leaf willow

Habit Trees, 5–20+ m. Stems: branches highly brittle at base, red-brown to yellow-brown, glabrous; branchlets gray-brown to red-brown, glabrous or pilose to villous. Plants 0.01–0.07 m, (dwarf), forming clonal mats by rhizomes.
Stems

trailing;

branches red-brown or yellow-brown, glabrous;

branchlets red-brown, glabrous.

Leaves

stipules rudimentary or foliaceous on early ones, usually foliaceous on late ones, (glands few or absent adaxially), apex acuminate, acute, or rounded;

petiole (margins covering groove, with spherical glands distally), (2–)3–10(–15) mm, glabrous or pilose adaxially;

largest medial blade (sometimes amphistomatous), very narrowly elliptic, lanceolate to narrowly lanceolate, or linear to lorate, (50–)70–103(–190) × (6–)7.5–17(–23) mm, 6–13 times as long as wide, base cuneate to convex, margins serrulate, apex acuminate, acute, or caudate, abaxial surface (not glaucous), glabrous or pilose, hairs white or ferruginous, wavy, adaxial slightly glossy, glabrous or pilose (especially on midribs);

proximal blade margins serrulate;

juvenile blade glabrous or pilose abaxially, hairs white and/or ferruginous.

(prominently marcescent, becoming skeletonized);

stipules absent or rudimentary;

petiole (deeply grooved or convex to flat adaxially), 1.2–3.2(–4.8) mm, (sparsely pubescent adaxially);

largest medial blade amphistomatous, (2 pairs secondary veins arising at or close to base, arcing toward apex), elliptic, broadly elliptic, obovate, subcircular, or circular, 7–15 × 3–11 mm, 1.1–2.5(–3.5) times as long as wide, base convex or cuneate, margins flat, entire, sometimes ciliate, apex convex, rounded, or retuse, abaxial surface not glaucous, glabrous, midrib sometimes pilose, hairs long, straight, wavy, or crinkled, adaxial highly glossy, glabrous;

proximal blade margins entire;

juvenile blade (green), glabrous abaxially or ciliate.

Staminate flowers

abaxial nectary 0.3–1 mm, adaxial nectary oblong to ovate, 0.2–0.6 mm, nectaries distinct or connate and shallowly cup-shaped;

stamens 4–6;

filaments hairy on proximal 1/2 or basally;

anthers 0.4–0.6 mm, (axes strongly recurved).

abaxial nectary absent, adaxial nectary narrowly oblong or oblong, 0.4–1.1 mm;

filaments distinct or connate less than 1/2 their lengths, glabrous;

anthers ellipsoid or obovoid, 0.3–0.5 mm.

Pistillate flowers

adaxial nectary oblong, (swollen), 0.2–0.5 mm;

stipe 0.5–1.5 mm;

ovary pyriform to obclavate, (rarely pilose), beak slightly bulged below styles;

ovules 12–16 per ovary;

styles 0.1–0.3 mm;

stigmas (sometimes 2 plump lobes), 0.2–0.28–0.36 mm.

abaxial nectary absent, adaxial nectary oblong or narrowly oblong, 0.4–1.6 mm, shorter than or equal to stipe;

stipe 0.4–1.4 mm;

ovary pyriform, sparsely to moderately densely short-silky or villous, at least on beaks, hairs ribbonlike, beak slightly bulged below styles;

ovules 12 per ovary;

styles connate or slightly distinct distally, 0.3–1 mm;

stigmas flat, abaxially non-papillate with rounded tip, or slenderly to broadly cylindrical, 0.16–0.34–0.52 mm.

Capsules

3–5 mm.

2.9–4.8 mm.

Catkins

staminate 35–83 × 7–13 mm, flowering branchlet 5–35 mm; pistillate 23–74(–80 in fruit) × 5–10 mm, flowering branchlet 6–35 mm;

floral bract 1–3 mm, apex acute or rounded, entire, abaxially sparsely hairy, hairs wavy; pistillate bract deciduous after flowering.

staminate 10–35 × 6–10 mm, flowering branchlet 1–11 mm; pistillate moderately densely flowered, stout or subglobose, 12–38 × 5–11 mm, flowering branchlet 3–14 mm;

floral bract brown, black, or bicolor, 1–1.3 mm, apex rounded, entire, abaxially sparsely hairy, hairs straight or wavy.

2n

= 38.

= 38.

Salix nigra

Salix phlebophylla

Phenology Flowering (south) early Feb-early May, (north) late Mar-early Jul. Flowering Jun–Jul.
Habitat Floodplains, edges of ponds and lakes, swamps, marshes, white cedar bogs, wet meadows, open fields, roadside ditches, mixed upland deciduous woods along streams Arctic-alpine, dry Dryas-lichen tundra, polygonal tundra with stone stripes and dry raised centers, scree and colluvial slopes, grass-sedge tussock tundra, sedge meadows in drainage ways, dwarf birch thickets, granitic and sandstone substrates
Elevation 10-1400 m (0-4600 ft) 0-2100 m (0-6900 ft)
Distribution
from FNA
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; NB; ON; QC; Mexico (Chihuahua)
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; NT; YT; e Asia (Chukotka, Russian Far East, arctic, e Siberia)
[BONAP county map]
Discussion

Hybrids:

Salix nigra forms natural hybrids with S. alba, S. amygdaloides, S. caroliniana, S. gooddingii, and S. lucida.

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

Hybrids:

Salix phlebophylla forms natural hybrids with S. arctica, S. fuscescens, and S. rotundifolia.

Salix phlebophylla × S. rotundifolia has hairy ovaries, some skeletonized leaves, a compact growth form that may lack rhizomes, and catkins with more than 15 flowers. It occurs on the Alaska arctic slope, outside the range of S. polaris.

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

Source FNA vol. 7, p. 36. FNA vol. 7, p. 74.
Parent taxa Salicaceae > Salix > subg. Protitea > sect. Humboldtianae Salicaceae > Salix > subg. Chamaetia > sect. Myrtosalix
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. 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. 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. nigra var. falcata, S. nigra var. lindheimeri
Name authority Marshall: Arbust. Amer., 139. (1785) Andersson: Proc. Amer. Acad. Arts 4: 72. (1858)
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