This is probably the most common willow in Illinois. Without the assistance of a beaver colony, it is difficult to control and its use is not recommended for wetland restorations. While willows are often difficult to identify, the Sandbar Willow can be readily recognized by its long slender leaves with widely spaced teeth. Other similar willows have teeth that are more densely spaced along the margins of their leaves, or their leaves lack distinct teeth altogether. Sometimes the Sandbar Willow is referred to as Salix exigua.

This native perennial shrub has two growth forms

Sandbar Willow has been collected from nearly all counties of Illinois (see Distribution Map); it is quite common and probably occurs in every county. Habitats include shrub swamps, borders of ponds and slow-moving rivers, gravel bars and sandbars, lake shore beaches, marshes, damp swales in prairies, and ditches. This weedy willow often appears in wet areas with a history of disturbance; it can reduce soil erosion.

Salix interior var. exterior Fernald:
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 interior var. wheeleri Rowlee:
Canada (North America)
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 interior var. pedicellata (Andersson) C.R. Ball:
Canada (North America)
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 interior Rowlee:
Canada (North America)
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 exigua subsp. interior (Rowlee) Cronquist:
Canada (North America)
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.

USA: AK , AR , CO , CT , DE , IL , IN , IA , KS , KY , LA , ME , MD , MA , MI , MN , MS , MO , MT , NE , NJ , NY , ND , OH , OK , PA , SD , TN , VT , VA , WV , WI , WY , DC (NPIN, 2007)

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

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

Salix interior is found in the following areas throughout North America:
USA (AK, AR, CO, CT, DC, DE, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, ND, NE, NJ, NY, OH, OK, PA, SD, TN, VA, VT, WI, WV, WY), CAN (AB, BC, MB, NB, NT, ON, QC, SK, YT)
(USDA NRCS, 2009)

It is considered a native species in the following areas:
Lower 48(Native), AK(Native), CAN(Native) (NPIN, 2007)

Overall This is a shrub. (Peattie, 1930)

Flowers There are 1-3 catkins often located together. Catkins are long and slender and loosely flowered. The scales are yellow, deciduous, and thinly pubescent. On male plants there are two stamens. On female plants stigmas are short and nearly sessile. (Peattie, 1930) Flowers may be yellow, green, or brown. (NPIN, 2007)

Fruit capsules are narrowly conic. (Peattie, 1930) Capsules are brown. (NPIN, 2007)

Leaves are smooth, narrow, and slightly toothed. There is a shallowly scalloped space between the short teeth. (Weatherbee, 2006) There are no stipules. Young leaves are thinly villous (pubescent with long and soft hairs that are not interwoven). Mature leaves are linear to elliptical and glabrous (hairless) beneath. Mature leaves have an acute base, a tip that is barely acute, and margins that are remotely denticulate (toothed). (Peattie, 1930) No other willow has such extremely long leaves in proportion to their breadth - 16 to 18 times as long as broad. There is consequently little shade under a sandbar willow. (NPIN, 2007)

Stems are numerous. Twigs are smooth and reddish brown. (Peattie, 1930)

Salix interior is considered a shrub willow species. Once established it grows numerous stems which become reddish brown with age. the bark of this species is generally smooth and does not become furrowed with age. Flowers often occur with 1-3 catkins together which are long and slender and loosely flowered. Scales are yellow in color, deciduous and thinly pubescent. Male flowers have two stamen and females stigma are short and sessile. On both, flowers may be green, brown or yellow.
Leaves are long, smooth and narrow with no stipules present. Young leaves are thinly pubescent which becomes lost with maturity. No other willow has such long leaves in proportion to their width, 16 to 18 times as long as broad. (Vestal, 1913, Symonds, 1963, NPIN, 2007, Rousseau, 1945, USDA NRCS, 2009)

Plant is 1.5-5.5 m tall. (Peattie, 1930)

Leaves 5-12 cm (2-4 3/4") long x 5-15 mm (1/8-5/8") wide. (Weatherbee, 2006)

Salix cordata (Sand Dune Willow) and Salix myricoides (blueleaf willow) are likely to be encountered on beaches as well. (Weatherbee, 2006)

Sandbar Willow has been collected from nearly all counties of Illinois (see Distribution Map); it is quite common and probably occurs in every county. Habitats include shrub swamps, borders of ponds and slow-moving rivers, gravel bars and sandbars, lake shore beaches, marshes, damp swales in prairies, and ditches. This weedy willow often appears in wet areas with a history of disturbance; it can reduce soil erosion.

Found in a variety of wet habitats. (Weatherbee, 2006) Found both in dunes and in low wet places. (Peattie, 1930)

Salix interior, as most willows is often found in wet areas, specifically sandbars, mudbars, and moist alluvial soils(Cutko, 2009). Other noted habitats include: Shrub swamps, borders of ponds and slow-moving rivers, gravel bars and sandbars, lake shore beaches, marshes, damp swales in prairies, and ditches(Argus, 1986).

Horizontal stems from the base of the clump are often rooting. (Peattie, 1930)

As a plant, the willow is a primary producer using photosynthesis to produce its food and energy. Best growing conditions include full sun, part shade, in moist sandy soils.

The flowers are pollinated primarily by bees and flies, including Cuckoo bees (Nomada spp.), Halictid bees, Andrenid bees, Syrphid flies, dance flies (Empis spp., Rhamphomyia spp.), thick-headed flies, Tachinid flies, and flesh flies. These insects seek nectar from the flowers, although some Halictid and Andrenid bees also collect pollen. The following oligolectic Andrenid bees are floral visitors of Sandbar Willow

Salix interior (Sandbar Willow)
(Short-tongued bees suck nectar or collect pollen, other insects suck nectar; information is available for staminate flowers only; Sandbar Willow often blooms later than other willows; 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; Apidae (Bombini): Bombus auricomus, Bombus pensylvanica; Anthophoridae (Ceratinini): Ceratina calcarata; Anthophoridae (Eucerini): Synhalonia speciosa; Anthophoridae (Nomadini): Nomada cressonii, Nomada cuneatus fq, Nomada denticulata fq, Nomada illinoiensis fq, Nomada integerrima fq, Nomada obliterata fq, Nomada ovatus fq, Nomada sayi fq, Nomada sulphurata, Nomada superba superba; Megachilidae (Megachilini): Megachile mendica

Bees (short-tongued)
Halictidae (Halictinae): Agapostemon sericea sn cp, Agapostemon splendens sn, Augochlora purus sn, Augochlorella aurata sn cp, Augochlorella striata sn, Halictus confusus sn cp, Halictus ligatus sn cp, Halictus rubicunda sn cp, Lasioglossum cinctipes sn cp, Lasioglossum cressonii sn, Lasioglossum forbesii sn fq, Lasioglossum foxii sn cp fq, Lasioglossum imitatus sn cp fq, Lasioglossum nymphaearum sn, Lasioglossum pectoralis sn, Lasioglossum pilosus pilosus sn, Lasioglossum tegularis sn cp, Lasioglossum truncatus sn, Lasioglossum versatus sn cp fq, Lasioglossum zephyrus sn cp fq; Halictidae (Sphecodini): Sphecodes cressonii sn, Sphecodes dichroa sn, Sphecodes minor sn; Colletidae (Colletinae): Colletes eulophi sn, Colletes inaequalis sn cp; Colletidae (Hylaeinae): Hylaeus affinis sn, Hylaeus illinoisensis sn fq, Hylaeus mesillae sn; Andrenindae (Andreninae): Andrena andrenoides andrenoides sn cp fq olg (Rb, Kr), Andrena carlini sn, Andrena crataegi sn, Andrena cressonii sn cp fq, Andrena erythrogaster sn cp fq olg (Rb, Kr), Andrena hippotes sn cp fq, Andrena illinoiensis sn cp fq olg, Andrena imitatrix imitatrix sn, Andrena macoupinensis sn, Andrena mandibularis sn, Andrena mariae sn cp fq olg, Andrena miserabilis bipunctata sn cp, Andrena personata sn, Andrena salictaria sn cp olg (Rb, Kr), Andrena sayi sn

Wasps
Sphecidae (Crabroninae): Lindenius columbianus, Oxybelus mexicanus, Oxybelis packardii; Sphecidae (Philanthinae): Philanthus gibbosus fq; Sphecidae (Sphecinae): Ammophila nigricans; Tiphiidae: Myzinum quinquecincta; Ichneumonidae: Calliephialtes notanda; Vespidae: Polistes fuscata

Flies
Bibionidae: Bibio femoratus, Bibio pallipes; Simuliidae: Cnephia pecuarum; Tabanidae: Chrysops striatus; Stratiomyidae: Nemotelus glaber; Syrphidae: Allograpta obliqua, Cheilosia capillata, Cheilosia punctulata, Chrysogaster antitheus, Eristalis dimidiatus fq, Eupeodes americanus, Ferdinandea dives, Helophilus fasciatus, Ocyptamus fascipennis, Orthonevra nitida, Paragus bicolor, Platycheirus obscurus, Platycheirus quadratus, Sphaerophoria contiqua fq, Syritta pipiens, Toxomerus geminatus fq, Toxomerus marginata, Trichopsomyia banksi; Empididae: Empis clausa, Empis desiderata, Empis distans, Rhamphomyia limbata fq, Rhamphomyia priapulus fq, Tachydromia maculipennis; Bombyliidae: Bombylius major; Conopidae: Myopa vesiculosa, Myopa vicaria, Zodion fulvifrons; Tachinidae: Chetogena claripennis, Gonia capitata, Linnaemya comta, Phasia purpurascens, Tachinomyia panaetius; Sarcophagidae: Helicobia rapax, Ravinia anxia, Sarcophaga sinuata; Calliphoridae: Cynomya cadaverina fq; Muscidae: Bithoracochaeta leucoprocta, Neomyia cornicina; Anthomyiidae: Delia platura fq; Otitidae: Chaetopsis aenea; Scathophagidae: Scathophaga furcata

Butterflies
Lycaenidae: Parrhasius m-album

Beetles
Chrysomelidae: Acalymma vittata fq; Coccinellidae: Coleomegilla maculata fq icp

Flower gender unspecified:

Bees (short-tongued)
Andrenidae (Andreninae): Andrena nida (Kr), Andrena nigrae (Kr)

Flowers of Salix interior are pollinated primarily by bees and flies, including Cuckoo bees (Nomada spp.), Halictid bees, Andrenid bees, Syrphid flies, dance flies (Empis spp., Rhamphomyia spp.), thick-headed flies, Tachinid flies, and flesh flies. These insects are primarily searching for nectar from within the flowers, but some bees do collect pollen. A number of organisms feed on the willow. Some of these include: aphids, leafhoppers, turtles, a number of caterpillars, as well as birds such as mallards, sparrows, grouse. (Knight, 1941, Evans, 1986)

Willows rely on wind to spread pollen from the male to the female flowers. When the shrubs are in full flower, it is easy to spot the difference between the male and female plants. After the pollen has been shed, the male pollen structures wither and fall off, and the female ovaries plump up with ripening seeds. The dense hairs on the leaves protect the plant from dessication due to the wind and the challenges of extreme temperatures. All willows have one scale per bud and are dioecious (sexes on separate plants). (Weatherbee, 2006)

Flowers in June, appearing after the leaves. (Peattie, 1930)

It is a perennial. (NPIN, 2007)

Salix interior begins to bloom in early spring and ends seed production by late spring. Willows rely on wind to spread pollen from the male to the female flowers. After the pollen has been shed, the male pollen structures wither and fall off, and the female ovaries plump up with ripening seeds. There is a high seed abundance at the end of the fruiting period which are generally spread in a rapid rate. For commercial purposes the use of stem cuttings for propagation has been developed. After plot establishment coppice silviculture is often used to boost growth and begin a new cycle.

The following is a representative barcode sequence, the centroid of all available sequences for this species.


No available public DNA sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 23
Specimens with Barcodes: 27
Species With Barcodes: 1

This plant is listed by the U.S. federal government or a state. Common names are from state and federal lists. In Maine sandbar willow is listed as Endangered. (USDA PLANTS, 2009)

Salix interior is only listed as an endangered species in the state of Maine.
All other locations have no conservation status both federally and state wide.
(USDA NRCS, 2009)

Infusion of stems and other plant parts used for side pains. (Rousseau, 1945) Willow and some other species of willow used for a scarlet dye. (Smith, 1933) Cut, peeled willows dipped in hot water to make them tough and pliable and made into baskets. (Gilmore, 1933) Wood used to make baskets, fish weirs and water jugs. (Chamberlin, 1911) Stems used to make bows and arrows. (Leighton, 1985)

salix interior has been domesticated for many economic uses. It is used by various agencies as a streambank stablaizer and young shoots may be used for livestock browse (USDA NRCS, 2009).
Numerous medicinal benefits have been recorded from the willow spp. mostly stemming from native american culture. This includes the infusion of stems and other plant parts used for side pains(Rousseau, 1945).
Stems have been used for basket weaving as well as for the use of bows and arrows in indigenous cultures. (Leighton, 1985)