Salicaceae -- Willow family

    J. A. Pitcher and J. S. McKnight

    Black willow (Salix nigra) is the largest and the only  commercially important willow of about 90 species native to North  America. It is more distinctly a tree throughout its range than  any other native willow; 27 species attain tree size in only part  of their range (3). Other names sometimes used are swamp willow,  Goodding willow, southwestern black willow, Dudley willow, and  sauz (Spanish). This short-lived, fast-growing tree reaches its   maximum size and development in the lower Mississippi River  Valley and bottom lands of the Gulf Coastal Plain (4). Stringent  requirements of seed germination and seedling establishment limit  black willow to wet soils near water courses (5), especially  floodplains, where it often grows in pure stands. Black willow is  used for a variety of wooden products and the tree, with its  dense root system, is excellent for stabilizing eroding lands.

This is probably the largest native willow in Illinois that is most likely to develop into a full-sized tree. Black Willow can be identified by its leaves, which are less pale on their undersides than the leaves of other Salix spp. (Willows). At least some of the leafy branches of Black Willow will have persistent stipules at the bases of the petioles, while other similar willows (e.g., Salix amygdaloides) have only deciduous stipules that soon fall off their branches.

This native tree is 30-90' tall at maturity, forming one to several trunks and an irregular crown that is usually more wide than tall. When there is a single trunk on a tree, it is usually short and stout; when multiple trunks are present, they are more narrow and lean away from each other. The bark trunk of old trees is mostly gray to nearly black and coarsely textured; it is covered with deep curving furrows. For younger trees, the bark trunk is grayish brown with shallow furrows and flattened ridges. The bark trunk is often discolored by the presence of various lichens. Twigs are usually pale brown and smooth, while the stems of young shoots are light green and pubescent. Alternate leaves that are 3-5' long and 1/4–2/3' across occur along the twigs and shoots. Leaf blades are linear-lanceolate in shape and finely serrated along their margins. Upper surfaces of the leaf blades are medium to dark green and hairless to nearly hairless, while their lower surfaces are more or less medium green, hairless to nearly hairless, and never whitened. Petioles are very short (¼' or less in length), light green to cream-colored, and often short-pubescent. The auriculate-ovate (ovate with ear-like lobes) stipules at the bases of the petioles are either persistent or deciduous and about 1/8' in length. Usually, on each tree, many leafy branches can be found with persistent stipules. Like other Salix spp., Black Willow is dioecious, producing either all male (staminate) or all female (pistillate) catkins on the same tree, but not both. The yellow to greenish white male catkins are 1-3' long, narrowly cylindrical in shape, and often curved; they are either ascending, widely spreading, or drooping. Each male catkin has numerous male florets that are arranged around its central axis in pseudo-whorls.. Each male floret has 3-5 stamens; at its base, there is a small pubescent bract and a tiny gland. The bract is narrowly oval in shape and a little shorter than the stamens; its coloration is typically pale yellow. The greenish female catkins become longer as they mature; they are 1-3' in length, cylindrical in shape, and either ascending or widely spreading. Each female catkin has many female florets that are arranged around its central axis in pseudo-whorls. Each female floret consists of a glabrous pistil with a pair of short stigmata at its apex and a short pedicel underneath. The pistil is flask-shaped (lanceoloid) with a slender beak and 3-5 mm. in length (1/8' to nearly 1/4' in length). The blooming period occurs during mid-spring as the leaves begin to develop for about 1-2 weeks. The florets are pollinated by insects and possibly by wind. Male florets soon wither away, while female florets transform into seed capsules that split open to release the tiny hair-covered seeds. These seeds are distributed by both wind and water. The woody root system has widely spreading lateral roots. Black Willow can reproduce by seeds, or it can reproduce from broken branches that take root in moist soil. At favorable sites, colonies of this tree sometimes occur.

Black willow is found throughout the eastern United States, adjacent
parts of Canada, and Mexico. Its range extends west from southern New
Brunswick and central Maine to Quebec, southern Ontario, central
Michigan, southeastern Minnesota, and eastern North Dakota. It occurs
south and west to the Rio Grande just below its confluence with the
Pecos River; and east along the Gulf Coast through the Florida Panhandle
and southern Georgia [5,8,11]. Black willow has been introduced in Utah
where it is now common along many streambottoms [17].

Black Willow is a common tree that is found in every county of Illinois. Habitats include bottomland woodlands that are prone to regular flooding, swamps, riverbanks and low areas along rivers, borders of lakes, gravelly seeps, and seasonal wetlands that dry out during the summer. At some bottomland woodlands along major rivers, Black Willow is occasionally the dominant or codominant tree. Sometimes Black Willow is found along ditches, where it is often mowed over or cut down to the stump level. However, new shoots are likely to develop in response to such setbacks. Because of its widely spreading lateral roots, which help to bind the soil, this tree is sometimes deliberately planted along waterways that are vulnerable to erosion. In general, soggy disturbed areas are preferred where some sunlight is available.

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This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

6 Upper Basin and Range
12 Colorado Plateau
14 Great Plains
16 Upper Missouri Basin and Broken Lands

AL AR CT DE FL GA IL IN IA KS
KY LA ME MD MA MI MN MS MO NE
NH NJ NY NC ND OH OK PA RI SC
TN TX UT VT VA WV WI MB NB ON
PQ MEXICO

Black willow is found throughout the Eastern United States and  adjacent parts of Canada and Mexico. The range extends from  southern New Brunswick and central Maine west in Quebec, southern  Ontario, and central Michigan to southeastern Minnesota; south  and west to the Rio Grande just below its confluence with the  Pecos River; and east along the gulf coast, through the Florida  panhandle and southern Georgia. Some authorities consider Salix  gooddingii as a variety of S. nigra, which extends  the range to the Western United States (3,9).

   
  -The native range of black willow.

Salix falcata Kunth:
Peru (South America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Salix nigra var. lindheimeri C.K. Schneid.:
Mexico (Mesoamerica)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Salix nigra Marshall:
Canada (North America)
United States (North America)
Mexico (Mesoamerica)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

This is the most common tree-sized willow in the Eastern US. (Weeks et al, 2005) One of the most extensive ranges across the country. (NPIN, 2007)

USA: AL , AR , CT , DE , FL , GA , IL , IN , IA , KS , KY , LA , ME , MD , MA , MI , MN , MS , MO , NE , NH , NJ , NY , NC , OH , OK , PA , RI , SC , TN , TX , VT , VA , WV , WI , DC (NPIN, 2007)

Canada: MB , NB , ON , QC (NPIN, 2007)

Native Distribution: S. New Brunswick and Maine south to NW. Florida, west to S. Texas, and north to SE. Minnesota; also from W. Texas west to N. California; local in N. Mexico; to 5000 (1524 m). (NPIN, 2007)

USDA Native Status: L48(N), CAN(N) (NPIN, 2007)

Canada

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

More info for the term: tree

Black willow is a small (sometimes shrublike) to large, short-lived,
deciduous tree [3,5,8,27,29]. It is fast growing and may reach maturity
within 30 years [8,17]. This tree usually obtains a height of 66 feet
(20 m) but can grow up to 138 feet (42 m) on some sites [8]. The
massive trunks are usually leaning and are often divided. The bark is
thick and deeply divided into furrows separating thick, scaly ridges.
The crown is broad and open with stout branches [27]. Twigs are slender
and easily detached [8]. Leaf blades are variable in size, the larger
to 4.7 inches (12 cm) long. Black willow roots are shallow and
laterally extensive [5,39].

Overall A brushy young pioneer to a large, spreading tree with black branches and trunks. (Hultman, 1978) Sometimes this may only be a shrub. (Peattie, 1930) The tree can grow very large. The wood is very brittle. It has a short, crooked, or leaning trunk with a spreading, open, irregular crown. (Weeks et al, 2005) There are often 1-4 leaning trunks. (UW, 2009) The tree has an open crown often with several trunks growing out at angles from one root. (NPIN, 2007)

Flowers The sexes are on different plants. Male flowers are accompanied by 1 or 2 small glands. Female flowers have a small flat gland near the base of the ovary. Each flower is subtended by a scale. Flowers and leaves appear together. Catkins are long and slender, with yellow deciduous scales. There are 3-5 stamens. Stigmas are nearly sessile. (Peattie, 1930) Flowers are slender and upright. (Weeks et al, 2005) There are sharply pointed buds. Catkins are on a long, leafy stalk. (UW, 2009) Bright yellow-green twigs bear yellow-green catkins. Flowers are inconspicuous and arranged in elongate clusters. (NPIN, 2007)

Fruit The capsule is ovate-conic, glabrous (hairless), and light reddish brown. (Peattie, 1930) Fruit is a cluster of capsules that release cottony seeds. (Weeks et al, 2005)

Leaves are narrow and green on both sides. (Hultman, 1978) Young leaves are much unlike the mature ones. Stipules are conspicuous, somewhat persistent, and halfheart-shaped. Young leaves are more or less downy. Mature leaves are lanceolate, long, curved-tapering, acute at base, finely serrate, thin, and bright green. (Peattie, 1930) Leaves are green on both top and bottom, smooth on both sides, and have finely toothed margins. Leaves are simple, very narrow, and elongate. Tips often curve. Often a pair of leafy stipules are at the base of the short leaf stalk. (Weeks et al, 2005) Leaves are usually hanging, narrowly lance-like, with both sides green but paler below, and edges mostly finely toothed and not curled. (UW, 2009)

Stems/branches are black. Branches are long and drooping. (Hultman, 1978) Twigs are round and limber. Twigs are reddish brown to pale orange, at first tomentose (closely covered with downy hairs). (Peattie, 1930) Branching is alternate. Bud with a single greenish brown, reddish, or yellow scale. Buds are small, flat, and somewhat triangular. Twigs are extremely slender and brittle and have various colors similar to the buds. Leaf scars are tiny with 3 bundle scars. (Weeks et al, 2005) Bright yellow-green twigs bear yellow-green catkins. (NPIN, 2007)

Bark is black. (Hultman, 1978) Bark is dark, flat, and scaly. (Peattie, 1930) Bark is dark brownish with thick, wide shaggy plates. MAture bark is dark brown to nearly black with thick, rough, shaggy patches that nearly interlace. Fissures are often deep. (Weeks et al, 2005)

Plant is 3-40'. (Hultman, 1978) Typically 30-40' tall, but can be much larger. (Weeks et al, 2005) Up to 65' tall. (UW, 2009) In the lower Mississippi Valley it attains commercial timber size, reaching 100-140' (30-42 m) in height. (NPIN, 2007)

Flowers are nearly 3" long. (Weeks et al, 2005) Catkins are 1"-3" long. (UW, 2009)

Fruit is 2.5" long. (Weeks et al, 2005)

Stems Trunks are up to 20" in diameter. (UW, 2009) In the lower Mississippi Valley it attains commercial timber size, reaching up to 4" (1.2 m) in diameter. (NPIN, 2007)

Leaves are 3-6" long. (Hultman, 1978) Leaves are up to 5" long. (NPIN, 2007)

Willows are a very difficult group to identify. (Peattie, 1930) This is the most common tree-sized willow in the Eastern US. Several introduced willows occur in the Midwestern US, including Salix babylonica (Weeping Willow) and Salix alba (White Willow). No other tree-sized willows have leaves that are green on both top and bottom and have finely toothed margins. (Weeks et al, 2005)

More info for the term: swamp

Black willow is most common on river margins where it occupies the
lower, wetter, and often less sandy sites. It is also common in swamps,
sloughs, swales, gullies, and drainage ditches, growing anywhere light
and moisture conditions are favorable [5]. It flourishes at or slightly
below water level and is not appreciably damaged by flooding and silting
[5,16]. On a flooded site in southern Illinois, black willow survived
32 or more days of complete inundation [16]. Black willow, however, is
not drought tolerant. Whole stands may die out when water tables lower
and soil drys up [39].

Soils: Black willow grows on a variety of soils but develops best in
fine silt or clay in relatively stagnant water. It thrives in saturated
or poorly drained soil from which other hardwoods are excluded [6,24].
Black willow is commonly found in moderately acidic (lower pH limit is
4.5) to near neutral soils [5].

Climate: Black willow grows best in climates characterized by an
average annual rainfall of 51 inches (130 cm), with approximately 20
inches (51 cm) falling from April through August. The average maximum
temperature across its range is 93 degrees Fahrenheit (34 deg C) in the
summer and 59 degrees Fahrenheit (15 deg C) in the winter [5].

Plant associates: Black willow is commonly associated with the
following species: eastern cottonwood, red maple (Acer rubrum), black
spruce (Picea mariana), river birch (Betula nigra), American sycamore
(Platanus occidentalis), boxelder (Acer negundo), red mulberry (Morus
rubra), swamp privet (Forestiera acuminata), buttonbush (Cephalanthus
occidentalis), water elm (Planera aquatica), and American elm (Ulmus
americana) [5,39].

More info for the terms: codominant, marsh, swamp

Black willow occurs as a codominant in some early seral floodplain
communities [24,30]. It codominates with sandbar willow (Salix exigua)
on floodplains having the greatest water depths and the longest
hydroperiods of any of the shallow freshwater swamps of the southern
United States [24]. Black willow also codominates with eastern
cottonwood (Populus deltoides) in the lower Mississippi Valley [30].
Published classifications listing black willow as a codominant in
community types (cts) are listed below:

Area Classification Authority

S. U.S. southern swamp & Penfound 1952
marsh cts
AR,MS: Lower cts Shelford 1954
Mississippi Valley

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This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

More info for the term: swamp

61 River birch - sycamore
63 Cottonwood
94 Sycamore - sweetgum - American elm
95 Black willow
101 Baldcypress
102 Baldcypress - tupelo
103 Water tupelo - swamp tupelo
235 Cottonwood - willow

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

FRES16 Oak - gum - cypress
FRES17 Elm - ash - cottonwood
FRES36 Mountain grasslands
FRES41 Wet grasslands

Black Willow is a common tree that is found in every county of Illinois. Habitats include bottomland woodlands that are prone to regular flooding, swamps, riverbanks and low areas along rivers, borders of lakes, gravelly seeps, and seasonal wetlands that dry out during the summer. At some bottomland woodlands along major rivers, Black Willow is occasionally the dominant or codominant tree. Sometimes Black Willow is found along ditches, where it is often mowed over or cut down to the stump level. However, new shoots are likely to develop in response to such setbacks. Because of its widely spreading lateral roots, which help to bind the soil, this tree is sometimes deliberately planted along waterways that are vulnerable to erosion. In general, soggy disturbed areas are preferred where some sunlight is available.

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This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

K091 Cypress savanna
K092 Everglades
K098 Northern floodplain forest
K101 Elm - ash forest
K113 Southern floodplain forest

Black willow is most commonly associated with the soil order  Entisols, particularly the Haplaquents and Fluvaquents derived  from alluvium. Willow grows on almost any soil, but its  extensive, shallow roots need an abundant and continuous supply  of moisture during the growing season.

    The species is most common on river margins and batture land,  where it occupies (and usually dominates) the lower, wetter, and  often less sandy sites. It is also common in swamps, sloughs, and  swales, and on the banks of bayous, gullies, and drainage  ditches, growing anywhere light and moisture conditions are  favorable. It flourishes at, or slightly below, water level and  is not appreciably damaged by flooding and silting (4).

    Although prevalent along most of the Mississippi River, it  produces the largest and best formed trees on very low, moist  sites in the batture of the lower river.

The climate in which black willow grows best is characterized by  an average rainfall of 1300 mm (51 in). Approximately 500 mm (20  in) of this occurs during the effective growing season, April  through August. The average maximum temperature is 34° C (93°  F) in the summer and 15° C (59° F) in the winter. In  parts of its range, black willow survives extremes of 46° to  -50° C (115° to -58° F). Geographic distribution  appears to be independent of temperature (4,7).

Common in wetlands. May act as pioneers at the waters edge. (Hultman, 1978) Occurs along streams and around sloughs and pools. (Peattie, 1930) The tree is common in low, wet ground along streams, lakes, ponds, ditches, and marshes. In old river channels it can attain it's largest size. (Weeks et al, 2005) Habitat consists of streambanks and meadows in alluvial soils. (UW, 2009) Native habitat includes stream banks, ditches, tanks, low ground, and other areas of wet soil. (NPIN, 2007)

Propagation by root sprouts is common. (Weeks et al, 2005) Seeds are wind-borne on silky hairs. (NPIN, 2007)

Because of their nectar and/or pollen, both male and female florets are visited by pollinating insects, especially bees and flies. Bee floral visitors include honeybees, bumblebees, Little Carpenter bees (Ceratina spp.), Cuckoo bees (Nomada spp.), Halictid bees (various species), and Andrenid bees (Andrena spp.). Among the Andrenid bees, Black Willow has been visited by such oligolectic bees as Andrenid andrenoides, Andrena bisalicis, Andrena erythrogaster, Andrena illinoiensis, and Andrena salictaria. Fly floral visitors include March flies (Bibio spp.), Dance flies (Rhamphomyia spp.), Syrphid flies (various spp.), and Tachinid flies (various spp.). Other insects feed on the leaves, wood, or other parts of Black Willow. These insects include thrips, aphids, leafhoppers (see Leafhopper Table), plant bugs (Lopidea salicis, Lygidea obscura, Orthotylus modestus, Orthotylus neglectus, & Orthotylus viridis), leaf beetles (see Leaf Beetle Table), the larvae of Long-Horned beetles (Cerambycidae), the caterpillars of the moths Catocala amatrix (The Sweetheart) and Catocala cara (Darling Underwing), the larvae of the sawfly Nematus ventralis (Willow Sawfly), and others. Various vertebrate animals also rely on Black Willow as a food source or as a provider of protective habitat. Both the Snapping Turtle (Chelydra serpentina) and Wood Turtle (Clemmys insculpta) feed on fallen willow leaves. The Ruffed Grouse, some ducks, and other birds feed on willow buds and catkins during the spring, when other sources of food are scarce. Some birds, including the Rusty Grackle, Yellow Warbler, and Warbling Vireo, occasionally use willows as the location of their nests. Black Willow is one of the trees that the Yellow-Bellied Sapsucker drills holes into so that it can feed on the sap. Deer and cattle are known to browse occasionally on the leaves and twigs of this tree, while beavers feed on the wood and use the branches in the construction of their dams and lodges. Photographic Location

Salix nigra (Black Willow)
(bees suck nectar or collect pollen, other insects suck nectar; information is available for staminate flowers only; a few observations are from Krombein et al. as indicated below, otherwise they are from Robertson; information about oligolegy in bees is from Krombein et al.)

On staminate flowers:

Bees (long-tongued)
Apidae (Apinae): Apis mellifera sn cp fq; Apidae (Bombini): Bombus griseocallis sn, Bombus pensylvanica sn; Anthophoridae (Ceratinini): Ceratina calcarata sn, Ceratina dupla dupla sn; Anthophoridae (Nomadini): Nomada cressonii sn, Nomada cuneatus sn fq, Nomada denticulata sn, Nomada illinoiensis sn fq, Nomada integerrima sn, Nomada obliterata sn fq, Nomada ovatus sn fq, Nomada sayi sn; Megachilidae (Osmiini): Osmia lignaria lignaria sn cp

Bees (short-tongued)
Halictidae (Halictinae): Agapostemon sericea sn cp, Augochlorella aurata sn, Augochlorella striata sn cp fq, Augochloropsis metallica metallica sn, Halictus confusus sn cp, Halictus ligatus sn cp, Halictus rubicunda sn cp, Lasioglossum cinctipes sn cp, Lasioglossum forbesii sn cp, Lasioglossum foxii sn cp fq, Lasioglossum imitatus sn cp fq, Lasioglossum macoupinensis sn, Lasioglossum pectoralis sn cp, Lasioglossum pilosus pilosus sn cp fq, Lasioglossum pruinosus sn cp, Lasioglossum tegularis sn cp, Lasioglossum versatus sn cp fq, Lasioglossum zephyrus sn cp fq, Paralictus cephalotes sn; Colletidae (Colletinae): Colletes inaequalis sn; Andrenidae (Andreninae): Andrena andrenoides andrenoides sn cp fq olg (Rb, Kr), Andrena bisalicis sn cp olg, Andrena carlini sn, Andrena crataegi sn cp fq, Andrena cressonii sn cp fq, Andrena dunningi sn cp, Andrena erythrogaster sn cp fq olg (Rb, Kr), Andrena forbesii sn, Andrena heraclei sn cp, Andrena hippotes sn cp, Andrena illinoiensis sn cp fq olg, Andrena imitatrix imitatrix sn cp, Andrena macoupinensis sn cp, Andrena mandibularis sn cp, Andrena miserabilis bipunctata sn cp fq, Andrena nigrae sn cp, Andrena nuda sn cp, Andrena personata sn, Andrena rugosa sn cp, Andrena salictaria sn cp fq olg (Rb, Kr), Andrena sayi sn cp fq

Wasps
Chrysididae: Chrysura pacifica; Braconidae: Agathis simillimus fq; Vespidae (Eumeninae): Ancistrocerus adiabatus

Flies
Bibionidae: Bibio albipennis albipennis, Bibio pallipes; Syrphidae: Allograpta obliqua, Cheilosia capillata, Cheilosia punctulata, Chrysogaster antitheus, Eristalinus aeneus, Eristalis arbustorum, Eristalis dimidiatus, Eupeodes americanus, Helophilus fasciatus, Psilota buccata, Sphaerophoria contiqua, Syritta pipiens, Syrphus ribesii, Toxomerus marginatus; Empididae: Rhamphomyia limbata, Rhamphomyia priapulus fq, Rhamphomyia sordida; Bombyliidae: Bombylius major; Conopidae: Myopa vesiculosa fq, Myopa vicaria fq, Zodion fulvifrons; Tachinidae: Archytas analis, Gymnosoma fuliginosum, Linnaemya comta, Siphona geniculata; Calliphoridae: Cynomya cadaverina; Muscidae: Neomyia cornicina; Anthomyiidae: Delia platura fq; Scathophagidae: Scathophaga furcata

Butterflies
Nymphalidae: Vanessa virginiensis; Pieridae: Colias philodice

Beetles
Cerambycidae: Molorchus bimaculatus; Chrysomelidae: Acalymma vittata; Lampyridae: Ellychnia corrusca

Flower gender unspecified:

Bees (short-tongued)
Colletidae (Hylaeinae): Hyaleus mesillae (Kr); Andrenidae (Andreninae): Andrena rubi (Kr)

In Great Britain and/or Ireland:
Foodplant / parasite
Uncinula adunca var. adunca parasitises Salix nigra

Black willow is the predominant species in Black Willow (Society  of American Foresters Type 95), a temporary, pioneer forest cover  type with excellent growth characteristics (1). It is an  associated species in the following cover types: River  Birch-Sycamore (Type 61), Cottonwood (Type 63),  Sycamore-Sweetgum-American Elm (Type 94), Baldcypress (Type 101),  Baldcypress-Tupelo (Type 102), Water Tupelo-Swamp Tupelo (Type   103), and Cottonwood-Willow (Type 235).

    Other noteworthy tree associates are red maple (Acer rubrum),  boxelder (A. negundo), red mulberry (Morus  rubra), and water locust (Gleditsia aquatica). In the  areas where willow develops best, swamp-privet (Forestiera  acuminata), buttonbush (Cephalanthus occidentalis), and  water-elm (Planera aquatica) are the major noncommercial  tree associates. Black willow often starts with sandbar willow  (Salix exigua), which dies out before reaching more than  small pulpwood size.

This tree is only occasionally browsed by white-tailed deer and rabbits. Ruffled grouse sometimes eat buds in winter. Principal value to wildlife is providing cover in aquatic habitats. Young saplings near water are a favorite site of red-winged blackbirds. Sapling stands along water's edge attract willow flycatchers and yellow warblers. Larger trees attract green-backed herons, yellow-crowned night herons, warbling vireos, eastern kingbirds, and others. Dead snags may be used by downy and red-bellied woodpeckers and subsequently by prothonotary warblers and tree swallows. The tree rarely lives long enough to develop cavities. (Weeks et al, 2005) The bark, tender twigs and buds are food for browsers such as deer, rabbits and beaver. These materials may be early season harvest for songbirds, waterfowl and small mammals. The flowers attract birds and butterflies. It is a larval host for Mourning Cloak (Nymphalis antiopa), Viceroy (Limenitis archippus), Red-spotted Purple, Viceroy and Tiger Swallowtail, and Acadian Hairstreak (Satyrium acadica). (NPIN, 2007)

Several insects attack live willow but  few cause serious damage. The forest tent caterpillar (Malacosoma  disstria), the gypsy moth (Lymantria dispar), the  cottonwood leaf beetle (Chrysomela scripta), the willow  sawfly (Nematus ventralis), and the imported willow leaf  beetle (Plagiodera versicolora) sometimes partially,  occasionally completely, defoliate willow trees, reducing growth  but seldom killing. Stem borers, such as the cottonwood borer  (Plectrodera scalator) attack willows and may kill by  girdling the base. Twig borers, like the willow-branch borer (Oberea  ferruginea), feed on the branches and cause deformities that  may be undesirable in ornamentals.

    Insects are frequently the vectors for disease organisms. Willow  blight, the scab and black canker caused by Pollaccia  saliciperda, is transmitted by borers. Members of the genus  Salix are the only known hosts. Phytophthora cactorum  causes bleeding canker, lesions on the lower trunk that  discharge a dark-colored, often slimy liquid. Confined to the  phloem and cambium area, it can result in death if the canker  girdles the trunk. Cytospora chrysosperma causes canker  in poplar and willow. Under forest conditions, cytospora canker  is of little consequence but when trees become weakened by  drought, competition, or neglect, losses can be heavy. In nursery  beds, losses of up to 75 percent of cuttings have been reported.  Leaf rust caused by Melampsora spp. is common on  seedlings throughout the range of black willow. Mistletoes (Phoradendron  spp.) damage and deform but seldom kill willows.

    The yellow-bellied sapsucker feeds on sap from holes they peck  through the bark; this early injury to the tree degrades the  lumber sawn later.

    Hot fires kill entire stands. Slow, light fires can seriously  wound willow, allowing woodrotting fungi to enter. Once dead,  willow deteriorates very rapidly. Top and branch rot account for  86 percent of the cull in willow.

More info for the term: density

Following a spring fast-moving head fire in a palm (Sabal spp.) grove in
south Texas, all black willow trees up to 13 feet (4 m) tall were
scorched badly and had few green leaves. Three months after the fire
all aboveground portions of black willow trees had died, but almost all
sprouted from the base. Following a low to moderate-severity Oklahoma
grassland summer fire, black willow density decreased. Preburn density
was 169 stems per acre (417 stems/ha); a year following the burn density
was only 51 stems per acre (125 stems/ha) [1].

Although black willow does exhibit some fire adaptations, it is very
susceptible to fire damage and will typically decrease following fire
[1]. High-severity fires can kill entire stands of black willow.
Low-severity fires can scorch the bark and seriously wound trees,
leaving them more susceptible to insects and disease [5,37]. Surface
fires will also destroy young seedlings and saplings [5,24,37].

More info for the terms: caudex, root crown

survivor species; on-site surviving root crown or caudex
off-site colonizer; seed carried by wind; postfire years 1 and 2
off-site colonizer; seed carried by animals or water; postfire yr 1&2

More info on this topic.

Black willow is a pioneer or early seral species commonly found along
the edges of rivers and streams, mud flats, and floodplains. This tree
is very shade intolerant and usually grows in dense, even-aged stands.
Black willow stands periodically stagnate and are eventually replaced by
more shade-tolerant trees such as American elm, sycamore (Platanus
spp.), ash (Fraxinus spp.), boxelder, and sweet gum (Liquidambar
styraciflua) [5,14,32,34,41].

More info for the terms: competition, cover, epigeal

Sexual reproduction: Black willows start producing seed when they are
about 10 years old [4,5]. Optimum seed-bearing age is from 25 to 75
years. The trees have good seed crops almost every year. producing an
average of 2.3 million seeds per pound (5 million/kg). Seeds ripen 45
to 60 days after catkins are pollinated by insects or wind. As the
seeds fall, the long silky hairs act as wings to carry the seeds long
distances. The seeds are also disseminated by water [5].

Seeds are not dormant. Viability is greatly reduced by only a few days
of dry conditions. Germination is epigeal, and germination capacity is
usually high. Very moist bare mineral soil is best for germination and
early development [5,14,28]. Once seedlings are established, full light
promotes vigorous growth. Seedlings grow rapidly in a favorable
environment, often exceeding 4 feet (1.2 m) in the first year. Low
ground cover competition and shade, however, greatly hampers growth
[28].

Vegetative reproduction: Root stocks of very young black willow trees
sprout prolifically. Propagation by cutting is the usual method of
artifical regeneration [5,39].

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More info for the term: phanerophyte

Phanerophyte (mesophanerophyte)
Phanerophyte (microphanerophyte)
Phanerophyte (nanophanerophyte)

More info for the terms: shrub, tree

Tree, Shrub

Burning has been shown to be beneficial in maintaining tallgrass
prairies by inhibiting the invasion of black willow and other woody
species [1].

Black willow will sprout from the base following fire [5,37]. Fires
that expose bare mineral soil may create a favorable seedbed for black
willow establishment. However, because seed viability is greatly
reduced by dry conditions [5], seedling establishment on burned sites
depends on the season of the burn, amount of moisture available, and
amount of exposed mineral soil.

Black willow has the ability to sprout from the base following fire
[37]. Its wind- and water-dispersed seeds are also important in
revegetating areas following fire. Fires are rare in the bottomland
areas where black willow typically occurs [1].

Black willow is less tolerant of  shade than any of its associates and may most accurately be  classed as very intolerant. It usually grows in dense, even-aged  stands, in which natural mortality is very heavy from sapling  stage to maturity. Trees fail to assert dominance, so willow  stands periodically stagnate. Stands not properly thinned may  lose up to 50 percent of their volume in 5 to 8 years (4).  Because of its intolerance and the absence of exposed mineral  soil under existing stands, willow does not succeed itself  naturally unless fresh sediment is deposited as the stand begins  to open up. Thinning should remove the understory trees and must  be light to prevent the heavy windthrow and stem breakage, which  is common in very open stands. Light, early, and frequent  thinning forestalls stagnation and mortality (2). An apparently  satisfactory thinning prescription is to leave a stand of about  14.9 to 17.2 m²/ha (65 to 75 ft²/acre) of basal area.  Heavy epicormic branching may result if weak trees are released.

Willow tends to be shallow rooted,  especially on clay-capped alluvial soils. It is seldom found on  soil types that undergo seasonal dehydration but is more often  present on soils with higher water tables throughout the summer  months. Floods may deposit more layers of alluvium in established  stands. New roots often develop from adventitious buds formed  within the previously exposed trunk. By this means, soil is   captured and held to form additional land areas along river  courses. Willows also sucker readily. Under certain conditions,  an essentially pure willow stand of 1 or more hectares (2.5  acres) may consist of relatively few clones.

Common with cattails. This plant plays a strong role in stabilizing and holding soil with strong roots. (Hultman, 1978)

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Black willow flowering begins in February in the southern portion of its
range and extends through late June at the northern limits. The catkins
usually appear at the time of or immediately preceding leaf emergence
[5,39]. Seeds ripen and fall in April to July [39].

Active growth period is the Spring and Summer. Bloom period is early spring. Fruit/seed period begins in Spring and ends in Summer. (USDA PLANTS, 2009) Flowers appear late April into May. The fruit ripens in May and seeds germinate immediately. (Weeks et al, 2005)

The tree is fast growing and short-lived, no longer than 85 years. (Weeks et al, 2005)

Root stocks of very young willow  trees sprout prolifically. Propagation by cuttings is the usual  method of artificial regeneration. With adequate moisture, good  cuttings, and sufficient cultivation to reduce competition from  other vegetation, first-year plantation survival can be close to  100 percent. Post-size willow cuttings have been rooted for use  in flood projects to prevent gullies (4).

Unless the willow seed is floating  on water, it must reach the seedbed within 12 to 24 hours because  viability is greatly reduced by only a few days of dry  conditions. Germination is epigeal. Germinative capacity is  usually high and no dormancy is known. Very moist, almost flooded  exposed mineral soil is best for satisfactory germination and  early development. Full light promotes vigorous growth once the   seedling is well established. In a favorable environment,  seedlings grow rapidly-often exceeding 1.2 in (4 ft) in height  the first year (4).

    Seedlings grow best when there is abundant moisture available  throughout the growing season. In the Mississippi Valley, average  heights are 9.8 in (32 ft) and average breast-high diameters are  6.6 cm (2.6 in) when the saplings are 5 years old (4).

Seed production usually  starts when the trees are about 10 years old, although viable  seeds can be obtained at younger ages. Optimum seed-bearing age  is from 25 to 75 years. The trees have good seed crops almost  every year, with only a few interspersed poor crops and rare  failures resulting from late freezes after flower buds have begun  to open. Large volumes of seeds are produced; they average 5  million/kg (2.3 million/lb). When the seeds fall, the long silky  hairs act as wings to carry the seeds very long distances. The  seeds are widely disseminated by wind and water.

Black willow is dioecious. No  consistently reliable morphological characteristics are  associated with the identification of the sexes. Male and female  are indistinguishable except during flowering and seed  development. In natural stands the sex ratio is probably 1 to 1,  as has been determined for other dioecious tree species,  including members of Salicaceae. Flowering begins in February in  the southern portion of the range and extends through late June  at the northern limits. The many-flowered catkins usually appear  at the time of or immediately preceding leafing out. Pollination  is mainly by insects; the flowers contain nectar. Pollen is also  carried by winds. The seed ripens quickly; 45 to 60 days after  pollination the small (3 to 6 mm or 0.12 to 0.24 in) light-brown  capsules begin to split open and shed minute green seeds that  have a hairy covering.

In natural stands of the lower  Mississippi Valley, 10-year-old trees average 15 in (49 ft) in  height and 14 cm (5.6 in) in d.b.h. In 20 years the trees will  average 22 in (72 ft) and 19 cm (7.5 in); in 40 years, 31 in (101  ft) and 49 cm (19.4 in). The tallest trees are 43 in (140 ft)  high; the largest diameters about 122 cm (48 in) (4). Black  willows in the North and those on poor sites in the South  generally reach a maximum height of 9 to 18 in (30 to 60 ft) and  15 to 46 cm (6 to 18 in) in d.b.h. These seldom furnish a  satisfactory saw log.

    In well-stocked stands on the best alluvial soils, particularly  along the Mississippi River, the tree prunes itself well and  produces an acceptably straight trunk which is clear of limbs for  an average of 12 in (40 ft). Open-grown willows and willows among  small streams and in swamps are generally limby and of limited  usefulness. Being a very weak tree, it is especially prone to  breakage; almost all large trees have large broken limbs (4).

    Unmanaged stands in the South have been estimated to yield 315 m³/ha  (50 cords/acre) at age 25 and 416 m³ (66 cords) at age 35.  The sawtimber volume (Scribner rule) in similar stands has been  estimated at 396 m³/ha (28,300 fbm/acre) at 35 years and 560  m³/ha (40,000 fbm/acre) at 50 years. Good sites sustain  about 30 m² of basal area per hectare (130 ft²/acre)  (4).

    Black willow is short lived; the greatest age recorded for a sound  tree is 70 years and for an unsound tree, 85 years. The average  black willow is mature in 55 years (4).

    Thinning increases yields and reduces mortality when carried out  in relatively young (18 to 24 yr) stands. Growth is best when  basal area is reduced by about one-half. Spacing between trees  after thinning should average 21 times the mean stem  diameter-25.4-cm (10-in) trees spaced 5.3 in (17.5 ft) apart. If  the factor is 18 or less, the spacing is probably too dense; if  24 or greater, the site is probably not fully utilized (2).

Population differences exist but the magnitude and distribution of  the variation of specific characters awaits verification through  analysis of provenance and progeny tests. Clonal differences in  defoliation of black willow by the cottonwood leaf beetle were  noted in experimental plots in Mississippi; feeding was also  heavier on the male clones (6). In another study, black willows  from two natural stands 160 km (100 mi) apart on the lower  reaches of the Mississippi River had significantly different  fiber lengths (8).

    One or more races of black willow are recognized as varieties by  some authorities (3,9). Western black willow (Salix nigra  var. vallicola Dudley) of Southwestern United States  and adjacent Mexico was renamed as a species, Goodding willow  (S. gooddingii Ball). Controversy over whether this is a  separate species or a varietal species of black willow still goes  on. Two other varieties have been named: S. nigra var.  altissima Sarg. of the Texas gulf coast and S. nigra  var. lindheimeri Schneid. of central Texas.

    Although the genus Salix is widely distributed and many  species occupy sympatric ranges, natural hybrids apparently are  not common (3). Putative hybrids are difficult to verify since  the identity of one parent is often uncertain. The following  willows hybridize with Salix nigra: Salix alba (S. x  hankensonii Dode), S. amygdaloides (S. x glatfelteri Schneid.),  S. bonplandiana, S. caroliniana, S. lucida (S. x schneideri  Boivan), and S. sericea.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 3
Specimens with Barcodes: 10
Species With Barcodes: 1

Canada

Rounded National Status Rank: NNR - Unranked

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Thinning: To increase yields and reduce mortality of black willow,
stands should be thinned as soon as economically feasible; thinning
should continue at 5-year intervals [5,28]. Spacing between trees after
thinning should average about 21 times the mean stem diameter of 10
inches (25.4 cm). This results in a 17.5 feet (5.3 m) spacing [5].

Insects and Disease: The forest tent caterpillar (malacosoma disstria),
the gypsy moth (Lymantria dispar), the cottonwood leaf beetle
(Chrysomila scripta), the willow sawfly (Nematus ventralis), and the
willow leaf beetle (Plagiodera versicolora) partially or occasionally
completely defoliate willow trees, reducing growth but seldom causing
death. The cottonwood borer (Plectrodera scalator) attacks black willow
and may kill by girdling the base. Top and branch rot account for 86
percent of the cull in willow. Leaf rust, fungus scab, and black canker
can cause leaf and shoot destruction of black willow seedlings [5,39].

Because of its weak wood and shallow roots, black willow is susceptible
to breakage and windthrow [39].

More info for the term: natural

Ancient pharmacopoeia recognized the bark and leaves of willow as useful
in the treatment of rheumatism [5]. Pioneering settlers boiled the bark
of black willow for its purgative and vermin-destroying powers [40]. In
1829, the natural glucoside, salicin, which is closely related
chemically to aspirin, was isolated from willow [5]. Black willow was
once used as a source of charcoal for gunpowder [8].

More info for the terms: competition, tree

Black willow was commonly used in soil stabilization projects in early
efforts at erosion control. Its flood tolerance and the ease with which
it establishes from cuttings continue to make it an excellent species
for reducing erosion of streambanks, bars, and islands [5,8,18,39].
Post-sized willow cuttings have been rooted for use in flood projects to
prevent gullies from forming [5].

Seeds lose viability rapidly if stored at room temperature.
Refrigerated storage of moistened seeds for no longer than 1 month is
recommended. Commercial seed is not usually available [39]. Planted
seedlings or cuttings should be protected from livestock, beavers, small
rodents, and rabbits. Hardware cloth placed around individual plants
will protect them from rodents and rabbits. Livestock should be
excluded by fencing the entire area, and firebreaks should surround the
revegetated area. Additionally, the area around each tree should be
kept free of weeds [18]. To reduce competition densities greater than
494 to 556 trees per acre (200-225 trees/ha) should be avoided [18].

More info for the term: cover

Black willow cover values in Utah are rated as follows [7]:

pronghorn - poor
elk - poor
moose - fair
small mammals - fair
small nongame birds - good
upland game birds - good
waterfowl - fair

More info for the term: resistance

Black willow is the largest and only commercially important willow in
North America. The wood is light, usually straight grained, and
moderately high in shock resistance. It stains and finishes well but is
relatively undurable [5]. The wood was once used extensively for
artifical limbs because it is lightweight, does not splinter easily, and
holds its shape well [5,8]. It is still used for making boxes and
crates, furniture core stock, turned pieces, table tops, wooden
novelties, doors, cabinets, polo balls, and toys [5,8,15]. Black willow
is also used for pulp [5,8].

Birds eat the buds and flowering catkins of black willow; deer eat the
twigs and leaves; and rodents eat the bark and buds [8,35]. The
yellow-bellied sapsucker feeds on the sap [5,39]. Black willow is
somewhat tolerant of grazing and browsing [39]. Black willow/cottonwood
stands are also commonly used as nesting habitat by some small nongame
bird species [30].

Black Willow prefers full or partial sun and wet to moist conditions. This tree adapts readily to a wide range of soil types, but it is more typical of heavy soil containing some clay or gravel, rather than sand. Black Willow grows rapidly, but it is rather short-lived. Because of its soft wood, this tree is prone to storm damage, and its widely spreading roots can clog water and sewer lines.

Black willow has been rated as fair in energy value and poor in protein
value [7].

Palatability of black willlow has been rated as fair for livestock and
deer [7,39].

The wood is light (specific gravity 0.34 to 0.41), usually  straight grained, without characteristic odor or taste, weak in  bending, compression, and moderately high in shock resistance. It  works well with tools, glues well, and stains and finishes well  but is very low in durability.

    The wood was once used extensively for artificial limbs, because  it is lightweight, doesn't splinter easily, and holds its shape  well. It is still used for boxes and crates, furniture core  stock, turned pieces, table tops, slack cooperage, wooden  novelties, charcoal, and pulp.

    Black willow was a favorite for soil stabilization projects in the  early efforts at erosion control. The ease with which the species  establishes itself from cuttings continues to make it an  excellent tree for revetments.

    Ancient pharmacopoeia recognized the bark and leaves of willow as  useful in the treatment of rheumatism. In 1829, the natural  glucoside salicin was isolated from willow. Today it is  the basic ingredient of aspirin, although salicyclic acid is  synthesized rather than extracted from its natural state.

Wood is weak, but still used for boxes and crates. It is extremely light and used for artificial limbs. (Hultman, 1978) It is used as a soil stabilizer in highly erodible stream banks. It is intolerant of shade. (Weeks et al, 2005)

This is not a preferred ornamental since the lifespan is moderate and the wood is susceptible to physical damage. (Weeks et al, 2005) Large trees are valuable in binding soil banks, thus preventing soil erosion and flood damage. Mats and poles made from Black Willow trunks and branches can provide further protection of riverbanks and levees. One of the lightest of all Eastern hardwoods, it is extremely weak in a structural sense. Yet it has a compliant strength. When nails are driven into it, black willow does not split. It is also a shade tree and honey plant. Ornamental uses include Fall conspicuous foliage, fast growing status, and shade trees. Medicinal uses include preparations of the bark of the roots that is intensely bitter and used to be an ingredient of spring tonics to purge the blood. Other uses include the numerous uses of the wood for millwork, furniture, doors, cabinetwork, boxes, barrels, toys, and pulpwood. During the American Revolution, the wood of black willow (and of other willows) was made into fine charcoal, which was then used to make gunpowder. The young stems are very flexible and are used in basket and furniture making. The twigs can be split in half lengthways, sun-dried and used as the foundation of coiled basketry. The plant is usually coppiced annually when grown for basket making. (NPIN, 2007)

Native American uses included the following. Various preparations of bark, roots, and leaves were used to check bowels, make the hair grow, as a poultice, for fever, for lost voice, for hoarseness, for "feebleness" due to thin blood, for stomach gas, for headaches, and on sprains and bruises. Bark and branches were used to construct various tools and containers. (UM, 2009)