Home/Species/ Prairie Willow

Salix humilis

Marsh.

Prairie Willow

G5Secure Found in 17 roadless areas NatureServe Explorer →

G5SecureGlobal Rank

LowThreat Impact

Identity

Unique IDELEMENT_GLOBAL.2.132284

Element CodePDSAL021E0

Record TypeSPECIES

ClassificationSpecies

Classification StatusStandard

Name CategoryVascular Plant

Endemicoccurs (regularly, as a native taxon) in multiple nations

KingdomPlantae

PhylumAnthophyta

ClassDicotyledoneae

OrderSalicales

FamilySalicaceae

GenusSalix

Other Common Names

prairie willow (EN) Saule humble (FR)

Concept Reference

Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

Taxonomic Comments

This record is for the broad treatment of Salix humilis as recognized by FNA (2010, vol. 7) and Kartesz (1994, 1999) which include S. humilis var. tristis. Weakley et al. (2023) recognize S. humilis var. tristis as the distinct species, S. occidentalis and thus recognize a narrower concept of S. humilis.

Conservation Status

Rank Method Rank calculation - Excel v3.2x

Review Date2024-09-03

Change Date1984-09-06

Edition Date2024-09-03

Edition AuthorsNordman, C. (2024).

Threat ImpactLow

Range Extent>2,500,000 square km (greater than 1,000,000 square miles)

Number of Occurrences> 300

Rank Reasons

Prairie Willow (Salix humilis) occurs in eastern North America, in eastern Canada and the eastern United States west to the Great Plains. There are estimated to be more than 1000 occurrences, including many occurrences with good or excellent viability. Threats to Prairie Willow include the loss of habitat due to conversion of its natural habitats for development or agriculture (such as for row crops or improved pasture), and competition from invasive exotic plants.

Range Extent Comments

Prairie Willow (Salix humilis) occurs in eastern North America, in eastern Canada and the eastern United States west to the Great Plains, it occurs in Canada from Nova Scotia, Newfoundland and Labrador across the Boreal Forest region of Québec, and Ontario (north to James Bay), to Manitoba, and in the United States from Maine to north Florida, west to the Dakotas and east Texas. Range extent was estimated to be about 6.35 million square kilometers, using herbarium specimens and photo-based observations documented between 1993 and 2024 (FNA 2010, GBIF 2024, iNaturalist 2024, POWO 2024, SEINet 2024).

Occurrences Comments

By applying a 1 km separation distance to herbarium records and photo-based observations documented between 1993 and 2024, there are estimated to be more than 1000 occurrences of Prairie Willow rangewide (GBIF 2024, iNaturalist 2024, SEINet 2024).

Threat Impact Comments

Threats to Prairie Willow include the loss of habitat due to conversion of its natural habitats for development or agriculture (such as for row crops or improved pasture), and competition from invasive exotic plants.

Ecology & Habitat

Habitat

Prairie Willow occurs at elevations of 20-1800 meters (FNA 2010, Weakley and Southeastern Flora Team 2024), Salix humilis var. humilis occurs in "dry mixed woods and forests, Black Spruce-Lichen woods, White Spruce-Balsam Fir forests, wet to dry prairies, grassy balds, loess bluffs, sandy stream terraces, coastal barrens, Sedge-Cattail meadows, on fine sand to rocky granitic, gneissic, limestone, and serpentine substrates" (FNA 2010), S. humilis var. tristis occurs in "moist limestone and serpentine barrens, open heath balds, open pine woods, moist prairies, swampy areas in open deciduous woods, and on stream banks" (FNA 2010).

Reproduction

Salix humilis var. humilis flowers in the north from early March to early June, and in the south from late January to late April, and S. humilis var. tristis flowers from early March to late May (FNA 2010).

Terrestrial Habitats

Forest/WoodlandShrubland/chaparralAlpineBarrens

Palustrine Habitats

HERBACEOUS WETLANDFORESTED WETLAND

Other Nations (2)

CanadaN5

Province	Rank	Native
New Brunswick	S5	Yes
Manitoba	S4	Yes
Quebec	SNR	Yes
Labrador	S4	Yes
Island of Newfoundland	S5	Yes
Prince Edward Island	S4	Yes
Ontario	S5	Yes
Nova Scotia	S5	Yes

United StatesN5

Province	Rank	Native
Missouri	SNR	Yes
Ohio	SNR	Yes
North Dakota	SNR	Yes
Arkansas	SNR	Yes
Connecticut	SNR	Yes
Oklahoma	SH	Yes
New York	S5	Yes
Georgia	SNR	Yes
Texas	SNR	Yes
North Carolina	S3	Yes
Pennsylvania	S5	Yes
Tennessee	SNR	Yes
Florida	S3	Yes
Kansas	SNR	Yes
Indiana	SNR	Yes
New Jersey	SNR	Yes
Alabama	S2	Yes
South Dakota	S1	Yes
New Hampshire	SNR	Yes
Kentucky	S4	Yes
Iowa	S4	Yes
Maryland	SNR	Yes
Rhode Island	SNR	Yes
Illinois	S3	Yes
Maine	SNR	Yes
Nebraska	SNR	Yes
Virginia	S5	Yes
Delaware	SNR	Yes
Michigan	SNR	Yes
Massachusetts	SNR	Yes
Minnesota	SNR	Yes
West Virginia	S5	Yes
Louisiana	SNR	Yes
Wisconsin	SNR	Yes
District of Columbia	SNR	Yes
South Carolina	SNR	Yes
Vermont	S5	Yes
Mississippi	SNR	Yes

Threat Assessments

Threat	Scope	Severity	Timing
1 - Residential & commercial development	Small (1-10%)	Serious or 31-70% pop. decline	High (continuing)
1.1 - Housing & urban areas	Small (1-10%)	Serious or 31-70% pop. decline	High (continuing)
2 - Agriculture & aquaculture	Small (1-10%)	Serious or 31-70% pop. decline	High (continuing)
2.1 - Annual & perennial non-timber crops	Small (1-10%)	Serious or 31-70% pop. decline	High (continuing)
8 - Invasive & other problematic species, genes & diseases	Restricted (11-30%)	Moderate or 11-30% pop. decline	High (continuing)
8.1 - Invasive non-native/alien species/diseases	Restricted (11-30%)	Moderate or 11-30% pop. decline	High (continuing)

Plant Characteristics

DurationDECIDUOUS, SPRING-FLOWERING

Economic Value (Genus)Yes

Roadless Areas (17)

Arkansas (1)

Area	Forest	Acres
Blue Mountain	Ouachita National Forest	9,755

Georgia (3)

Area	Forest	Acres
Ben Gap	Chattahoochee National Forest	1,292
Kelly Ridge	Chattahoochee National Forest	8,325
Sarah's Creek	Chattahoochee National Forest	6,888

New Hampshire (4)

Area	Forest	Acres
Carr Mountain	White Mountain National Forest	17,110
Cherry Mountain	White Mountain National Forest	8,766
Sandwich Range	White Mountain National Forest	16,797
Waterville	White Mountain National Forest	4,312

North Carolina (4)

Area	Forest	Acres
Big Indian (addition)	Nantahala National Forest	1,155
Graveyard Ridge (addition)	Pisgah National Forest	1,958
Laurel Mountain	Pisgah National Forest	5,683
Sam Knob (addition)	Pisgah National Forest	2,576

Virginia (3)

Area	Forest	Acres
Elliott Knob	George Washington National Forest	9,380
Kelley Mountain	George Washington National Forest	7,590
Little River	George Washington National Forest	27,292

West Virginia (1)

Area	Forest	Acres
Dry River (WV)	George Washington National Forest	7,331

Wisconsin (1)

Area	Forest	Acres
09154 - St. Peters Dome	Chequamegon-Nicolet National Forest	4,002

References (7)

Flora of North America Editorial Committee (FNA). 2010. Flora of North America north of Mexico. Vol. 7. Magnoliophyta: Salicaceae to Brassicaceae. Oxford University Press, New York. xxii + 797 pp.
Global Biodiversity Information Facility (GBIF). 2024. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2024).
iNaturalist. 2024. Online. Available: https://www.inaturalist.org (accessed 2024).
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Plants of the World Online (POWO). 2024. Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Online. Available: https://powo.science.kew.org/ (accessed 2024).
Southwest Environmental Information Network (SEINet). 2024. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2024).
Weakley, A.S., and Southeastern Flora Team. 2024. Flora of the southeastern United States. Edition of March 4, 2024. University of North Carolina Herbarium (NCU), North Carolina Botanical Garden, University of North Carolina, Chapel Hill. 2203 pp.

Salix humilis

Habitat

Reproduction

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