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weeping willow

American willow, pussy or large pussy willow, pussy willow

Habit Shrubs, 2–4(–8) m, (sometimes forming clones by stem fragmentation).
Stems

branches yellow-brown to red-brown;

branchlets sparsely to moderately densely tomentose, especially at nodes.

branches dark red-brown or yellow-brown, not to strongly glaucous, villous to glabrescent, (peeled wood smooth or striate, striae sometimes very dense, to 10 mm);

branchlets yellowish, red-brown, or yellow-brown, or dark brown, moderately densely velvety, velutinous, or tomentose to glabrescent.

Leaves

stipules absent or rudimentary on early ones;

petiole convex to flat or shallowly to deeply grooved adaxially, 7–9 mm, tomentose abaxially;

largest medial blade lanceolate, narrowly oblong, or narrowly elliptic, 90–160 × 5–20 mm, 5.5–10.5 times as long as wide, base cuneate, margins flat, spinulose-serrulate or serrulate, apex acuminate, caudate, or acute, surfaces glabrous or sparsely short-silky, hairs straight, dull adaxially;

proximal blade margins entire;

juvenile blade reddish or yellowish green.

stipules rudimentary on early ones, foliaceous on late ones, (0.8–12.5 mm), apex acute to acuminate;

petiole convex to flat adaxially, 6–17 mm, tomentose adaxially;

largest medial blade narrowly elliptic, elliptic, oblanceolate, or obovate, 30–80(–135) × 12–33 mm, (2.3–)3–3.5(–4.5) times as long as wide, base convex or cuneate, margins flat, crenate, irregularly toothed, sinuate, or entire, apex acute, convex, or acuminate, abaxial surface glaucous, glabrous, pilose, sparsely pubescent or long-silky, midrib glabrous or densely pubescent, hairs (white, sometimes also ferruginous), wavy, adaxial dull or slightly glossy, glabrous or pilose, (hairs rarely ferruginous);

proximal blade margins entire or serrulate;

juvenile blade reddish or yellowish green, pilose, tomentose or moderately densely short-silky abaxially, hairs white and ferruginous.

Staminate flowers

abaxial nectary 0.2–0.6 mm, adaxial nectary oblong or ovate, 0.4–0.7 mm, nectaries distinct or connate and cup-shaped;

filaments distinct, hairy on proximal 1/2 or basally;

anthers (sometimes reddish turning yellow), ellipsoid or globose.

adaxial nectary oblong, 0.6–1.1 mm;

filaments distinct, glabrous or hairy basally;

anthers yellow or purple turning yellow, ellipsoid or short- or long-cylindrical, 0.5–1 mm.

Pistillate flowers

adaxial nectary oblong, square, ovate, or obovate, 0.4–0.8 mm;

ovary ovoid or obturbinate, beak (sometimes pilose proximally), slightly bulged below or abruptly tapering to styles;

ovules 2–4 per ovary;

styles distinct or connate 1/2 their lengths, 0.2–0.3 mm;

stigmas flat, abaxially non-papillate with rounded tip, or 2 plump lobes (almost capitate), 0.2–0.3 mm.

adaxial nectary oblong or ovate, 0.7–1.3 mm, shorter than stipe;

stipe 1.6–2.7 mm;

ovary obclavate or pyriform, short-silky (hairs straight), beak sometimes slightly bulged below styles;

ovules 6–16 per ovary;

styles 0.3–1 mm;

stigmas slenderly or broadly cylindrical, 0.48–0.64–0.88 mm.

Capsules

2–2.7 mm.

6–11 mm.

Catkins

(flowering just before leaves emerge); staminate 13–35 mm, flowering branchlet 1–6 mm; pistillate densely flowered, stout or subglobose, 9–27 × 2.5–7 mm, flowering branchlet (0–)2–4 mm;

floral bract 1.1–1.8 mm, apex acute, rounded, or truncate, entire, abaxially sparsely hairy throughout or proximally, hairs wavy.

flowering before leaves emerge; staminate stout or subglobose, 23–52 × 12–22 mm, flowering branchlet 0–3 mm; pistillate densely flowered (loose in fruit), slender or stout, 25–108(–135 in fruit) × 12–33 mm, flowering branchlet 0–10 mm;

floral bract brown, black, or bicolor, 1.4–2.5 mm, apex acute or convex, abaxially hairy, hairs straight.

2n

= 76.

= 76, 95, 114.

Salix babylonica

Salix discolor

Phenology Flowering spring. Flowering early Apr-late May.
Habitat Around settlements Marshy margins of ponds, streams, and open alluvial woods, fens, seepage areas, peaty substrates
Elevation ca. 50 m (ca. 200 ft) 0-2400 m (0-7900 ft)
Distribution
from FNA
AL; AR; CA; DC; DE; FL; GA; KY; LA; MD; NC; SC; TN; VA; Asia [Introduced in North America; introduced also in Mexico (Mexico City), South America]
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; CT; DE; IA; ID; IL; IN; KY; MA; MD; ME; MI; MN; MO; MT; NC; ND; NH; NJ; NY; OH; PA; RI; SD; VT; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK
[WildflowerSearch map]
[BONAP county map]
Discussion

Little is known about the origin of the strongly weeping cultivar of Salix babylonica. It was described by Linnaeus (1737[1738]) based on young garden specimens (W. J. Bean 1970–1988, vol. 4). It is thought to have originated in China, although it no longer occurs in the wild and its origin is uncertain. Selections are thought to have been transported to Europe along the trade route from China. In Tajikistan, there are three cultivated clones, one of which is staminate (A. K. Skvortsov 1999). Taxonomic treatments of S. babylonica are variable. Some botanists recognize a single species, including both pendulous and non-pendulous forms (Skvortsov), while others recognize four species: S. babylonica, with a weeping habit, S. capitata Y. L. Chou & Skvortsov, S. pseudolasiogyne H. Léveillé, and the commonly cultivated S. matsudana Koidzumi (Fang Z. F. et al. 1999), with an erect or spreading habit. Here, S. babylonica is treated in a narrow sense, including only weeping forms.

Salix babylonica is not cold tolerant and is not commonly grown in Europe (R. D. Meikle 1984) or in northern North America. In the flora area, cultivated trees with strongly pendulous branches and branchlets have been identified as S. babylonica (G. W. Argus 1985, 1986, 1993), but many are hybrids with S. alba (S. ×sepulcralis) or S. euxina (S. ×pendulina). Salix ×sepulcralis, especially nothovar. chrysocoma, with bright yellow branchlets, is the most commonly grown of these hybrids. All reported occurrences of S. babylonica need verification.

Hybrids:

Salix ×sepulcralis Simonkai: Weeping willow, S. alba × S. babylonica, is introduced from Europe and widely naturalized throughout the world. Synonyms include S. ×salamonii Carrière ex Henry and S. ×sepulcralis nothovar. chrysocoma (Dode) Meikle. It is characterized by: trees, to 12 m, stems pendulous; branches somewhat to highly brittle at base, yellowish, yellow-green, or yellow-brown; branchlets yellowish, yellow-green, or golden; stipules rudimentary or foliaceous on late leaves; petiole not glandular or with pairs or clusters of spherical glands distally or scattered throughout, short-silky adaxially; largest medial blade amphistomatous or hemiamphistomatous, narrowly elliptic to very narrowly so, margins finely serrulate or spinulose-serrulate, abaxial surface glaucous, adaxial glaucous, sparsely long-silky to glabrescent, hairs white or white and ferruginous, adaxial surface slightly glossy; catkins on distinct flowering branchlet 3–14 mm; staminate moderately densely flowered, slender, 23–53 × 3–9 mm; pistillate moderately densely to loosely flowered, slender to stout, 18–30 × 3–8 mm, flowering branchlet 3–14 mm; pistillate bracts persistent after flowering; staminate abaxial and adaxial nectaries distinct; stamens 2; anthers 0.5–0.8 mm; pistillate nectary longer than stipe; stipe 0–0.2 mm; ovaries gradually tapering to styles; ovules 4 per ovary; styles 0.15–2 mm; capsules 1–2 mm. In the flora area, it occurs in: British Columbia, New Brunswick, Nova Scotia, Ontario, Quebec; Alaska, Arizona, Arkansas, California, Connecticut, District of Columbia, Illinois, Iowa, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Missouri, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oregon, Pennsylvania, Tennessee, Utah, Virginia, and West Virginia.

The most commonly cultivated, and sometimes escaped, weeping willow with golden or yellow-green branchlets is Salix ×sepulcralis nothovar. chrysocoma (Dode) Meikle. It probably originated as S. alba var. vitellina × S. babylonica (R. D. Meikle 1984). According to F. S. Santamour Jr. and A. J. McArdle (1988), S. ×sepulcralis cv. Salamonii has a broadly pyramidal crown and is only slightly pendulous. It is not clear just how this cultivar differs from S. ×pendulina. For a discussion of the taxonomy of these and other weeping willows see J. Chmela (1983).

Salix ×pendulina Wenderoth: Weeping willow, S. babylonica × S. euxina, is introduced from Europe and grown throughout the world. It is characterized by: trees, 2.5–12 m, stems pendulous; branches highly brittle at base, yellow-brown, gray-brown, or red-brown; branchlets yellowish to brownish; stipules foliaceous on late leaves; petioles glabrous, pilose, or velvety to glabrescent adaxially; largest medial blade amphistomatous or hypostomatous, very narrowly elliptic to lanceolate, or linear, margins serrulate, irregularly so, or spinulose-serrulate, abaxial surface glaucous, adaxial slightly glossy or dull; catkins on distinct flowering branchlet, 3–14 mm; staminate loosely flowered, stout, 16–34 × 7–11 mm; pistillate densely or moderately densely flowered, slender or stout, 20–36 × 3.5–11 mm; pistillate bract persistent after flowering; staminate abaxial and adaxial nectaries connate and shallowly cup-shaped; stamens 2; anthers 0.5–0.6 mm; pistillate nectary longer than stipe; stipe 0 mm; styles 0.2–0.6 mm; ovules 4–8 per ovary; capsules 1.8–3.5 mm. In the flora area, it occurs in: Ontario; California, Connecticut, District of Columbia, Georgia, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Missouri, Nebraska, New Jersey, New Mexico, New York, North Carolina, Ohio, Oregon, Pennsylvania, Texas, Virginia, Washington, and West Virginia.

Reports of this hybrid in British Columbia and California are undocumented. Plants of Salix ×pendulina with prominent, caudate stipules are var. blanda (Andersson) Meikle; those with ovaries with patchy or streaky hairiness are var. elegantissima (K. Koch) Meikle.

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

Salix discolor is introduced in North Carolina.

Vegetative specimens of Salix discolor can be difficult to distinguish from S. planifolia, but there are two, somewhat variable, characters that can be used. Salix discolor usually has leaves dull adaxially, with arcuate secondary veins widely and irregularly spaced; S. planifolia has leaves slightly or highly glossy adaxially, with straight secondary veins closely and regularly spaced.

Salix discolor in northeastern United States can be difficult to distinguish from widely naturalized S. atrocinerea and S. cinerea. Useful diagnostic characters are: tertiary leaf veins, which are irregular in S. discolor but close and parallel in introduced species, and raised striae on peeled 3–5-year old branches, which are absent or indistinct and relatively short in S. discolor, but long and very prominent in the introductions.

Hybrids:

Salix discolor forms natural hybrids with S. humilis, S. interior, S. myricoides, S. pellita, and S. planifolia. Reports of hybrids with S. candida and S. eriocephala (M. L. Fernald 1950), and S. bebbiana and S. pyrifolia (C. K. Schneider 1921; Fernald), are not based on convincing specimens. Synthetic hybrids with S. bebbiana could not be made (G. W. Argus 1974; A. Mosseler 1990) and those made with S. eriocephala had low seed viability (Mosseler).

Salix discolor × S. humilis has tomentose leaves of S. humilis and longer catkins and styles of S. discolor (G. W. Argus 1986). These species readily hybridize and produce abundant seed (Argus 1974). The hybrids are fertile and backcross. Specimens of S. discolor with densely villous branchlets may be hybrids or introgressants with S. humilis. The two species usually are ecologically isolated; S. discolor occurs in wetland thickets and S. humilis in dry, sandy upland forests. Where the two habitats come into proximity, hybrids occur but large swarms have not been observed.

Salix discolor × S. myricoides (S. ×laurentiana Fernald, syn. S. paraleuca Fernald) usually resembles S. myricoides but has hairy ovaries (R. D. Dorn 1975, 1976). This hybrid was originally described as a species, from lower St. Lawrence River, Quebec. Its most distinctive feature is that hairs appear on ovaries in patches, at the base or, sometimes, only on the stipes. A similar ovary indumentum pattern appears in other hybrids or species of hybrid origin, e.g., S. hookeriana. Characteristics of S. discolor found in S. ×laurentiana include epidermis with gray-margined splits, leaf margins entire or sinuate, leaves with 2–4 teeth per cm, anthers yellow or purple, filaments hairy on proximal half or basally, ovaries hairy, greenish brown or green with red sutures, and adaxial pistillate nectaries ovate. Characteristics of S. myricoides include inner bud-scale membranes separating from the outer ones, stipules more prominent, catkins on distinct flowering branchlets, and longer styles sometimes distinct about half their lengths. This hybrid occurs throughout the area of overlap of the parents. All three taxa often are intermixed but few hybrids seem to produce well-developed seed.

Salix discolor × S. pellita (S. ×pedunculata Fernald) is characterized by juvenile leaves with infolded or sometimes revolute margins, ovaries with patches of hairs relatively short, flattened, crinkled, and refractive, and catkins borne on distinct flowering branchlets 2–10 mm. This sporadic hybrid does not seem to be fertile. It occurs in Newfoundland, Quebec, and Saskatchewan. Although it has been collected at few localities, it probably is more common and should be expected wherever the two species grow together. The type and other collections compare very well with synthetic hybrids (A. Mosseler 1990), which were reported to show a high hybridization success rate, high F1 pollen viability, and high seedling viability. It was suggested that variability within these species may be due to interspecific gene flow. In interpreting the parentage of the wild hybrids it is not possible to rule out hybridization of S. planifolia or S. myricoides with S. pellita, or that these hybrids may be S. myricoides × S. planifolia, as suggested by B. G. O. Floderus (1939). Salix ×pellicolor Lepage is a later synonym of this hybrid.

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

Source FNA vol. 7, p. 40. FNA vol. 7, p. 126.
Parent taxa Salicaceae > Salix > subg. Salix > sect. Subalbae Salicaceae > Salix > subg. Vetrix > sect. Cinerella
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. 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. 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. ancorifera, S. discolor var. overi, S. discolor var. prinoides
Name authority Linnaeus: Sp. Pl. 2: 1017. (1753) Muhlenberg: Ges. Naturf. Freunde Berlin Neue Schriften 4: 236, plate 6, fig. 1. (1803)
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