Melilotus officinalis - (L.) Lam.
Other English Common Names: Yellow Sweetclover
Other Common Names: yellow sweetclover
Taxonomic Status: Accepted
Related ITIS Name(s): Melilotus officinalis (L.) Lam. (TSN 26150)
Unique Identifier: ELEMENT_GLOBAL.2.146387
Element Code: PDFAB2H060
Informal Taxonomy: Plants, Vascular - Flowering Plants - Pea Family
Kingdom Phylum Class Order Family Genus
Plantae Anthophyta Dicotyledoneae Fabales Fabaceae Melilotus
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Concept Reference
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.
Concept Reference Code: B94KAR01HQUS
Name Used in Concept Reference: Melilotus officinalis
Conservation Status

NatureServe Status

Global Status: GNR
Global Status Last Changed: 22Mar1994
Rounded Global Status: GNR - Not Yet Ranked
Nation: United States
National Status: NNA
Nation: Canada
National Status: NNA (13Oct2016)

U.S. & Canada State/Province Status
United States Alabama (SNA), Alaska (SNA), Arizona (SNA), Arkansas (SNA), California (SNA), Colorado (SNR), Connecticut (SNA), Delaware (SNA), District of Columbia (SNA), Florida (SNA), Georgia (SNR), Hawaii (SNA), Idaho (SNA), Illinois (SNA), Indiana (SNA), Iowa (SNA), Kansas (SNA), Kentucky (SNA), Louisiana (SNA), Maine (SNA), Maryland (SNA), Massachusetts (SNR), Michigan (SNA), Minnesota (SNA), Mississippi (SNA), Missouri (SNA), Montana (SNA), Nebraska (SNA), Nevada (SNA), New Hampshire (SNA), New Jersey (SNA), New Mexico (SNA), New York (SNA), North Carolina (SNA), North Dakota (SNR), Ohio (SNA), Oklahoma (SNA), Oregon (SNA), Pennsylvania (SNA), Rhode Island (SNA), South Carolina (SNA), South Dakota (SNA), Tennessee (SNA), Texas (SNA), Utah (SNA), Vermont (SNA), Virginia (SNA), Washington (SNA), West Virginia (SNA), Wisconsin (SNA), Wyoming (SNA)
Canada Alberta (SNA), British Columbia (SNA), Labrador (SNA), Manitoba (SNA), New Brunswick (SNA), Newfoundland Island (SNA), Northwest Territories (SNA), Nova Scotia (SNA), Ontario (SNA), Prince Edward Island (SNA), Quebec (SNA), Saskatchewan (SNA), Yukon Territory (SNA)

Other Statuses

NatureServe Global Conservation Status Factors

Other NatureServe Conservation Status Information

U.S. States and Canadian Provinces
Color legend for Distribution Map
NOTE: The distribution shown may be incomplete, particularly for some rapidly spreading exotic species.

U.S. & Canada State/Province Distribution
United States AKexotic, ALexotic, ARexotic, AZexotic, CAexotic, CO, CTexotic, DCexotic, DEexotic, FLexotic, GA, HIexotic, IAexotic, IDexotic, ILexotic, INexotic, KSexotic, KYexotic, LAexotic, MA, MDexotic, MEexotic, MIexotic, MNexotic, MOexotic, MSexotic, MTexotic, NCexotic, NDexotic, NEexotic, NHexotic, NJexotic, NMexotic, NVexotic, NYexotic, OHexotic, OKexotic, ORexotic, PAexotic, RIexotic, SCexotic, SDexotic, TNexotic, TXexotic, UTexotic, VAexotic, VTexotic, WAexotic, WIexotic, WVexotic, WYexotic
Canada ABexotic, BCexotic, LBexotic, MBexotic, NBexotic, NFexotic, NSexotic, NTexotic, ONexotic, PEexotic, QCexotic, SKexotic, YTexotic

Range Map
No map available.

Ecology & Life History Not yet assessed
Economic Attributes Not yet assessed
Management Summary Not yet assessed
Population/Occurrence Delineation Not yet assessed
Population/Occurrence Viability
U.S. Invasive Species Impact Rank (I-Rank)
Disclaimer: While I-Rank information is available over NatureServe Explorer, NatureServe is not actively developing or maintaining these data. Species with I-RANKs do not represent a random sample of species exotic in the United States; available assessments may be biased toward those species with higher-than-average impact.

I-Rank: Medium/Low
Rounded I-Rank: Medium
I-Rank Reasons Summary: This is a widespread exotic species with some evidence that it can alter soil nitrogen, at least in nitrogen-poor systems. It requires some disturbance to become established and is often found on roadsides but it also impacts recovering prairies and other sites of greater biodiversity value. It is still widely planted.
Subrank I - Ecological Impact: Medium
Subrank II - Current Distribution/Abundance: High/Medium
Subrank III - Trend in Distribution/Abundance: Medium/Low
Subrank IV - Management Difficulty: Medium
I-Rank Review Date: 19Dec2005
Evaluator: Fellows, M., rev. Maybury (2005).
Native anywhere in the U.S?
Native Range: Mediterranean regions from central Europe to Tibet (Eckardt 1987).

Download "An Invasive Species Assessment Protocol: Evaluating Non-Native Plants for their Impact on Biodiversity". (PDF, 1.03MB)
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Screening Questions

S-1. Established outside cultivation as a non-native? YES
Comments: (Kartesz 1999).

S-2. Present in conservation areas or other native species habitat? Yes
Comments: Many Midwestern native prairies and open, unflooded communities (Cole 1990).

Subrank I - Ecological Impact: Medium

1. Impact on Ecosystem Processes and System-wide Parameters:Moderate significance
Comments: Nitrogen-fixing, which may change the species composition of invaded areas (Eckardt 1987; Weber 2003). Some sources say it is more of an aesthetic than ecological issue (Eckardt 1987); however, work in very low-nitrogen Badlands sparse vegetation demonstrated that this species increased soil nitrogen, which presumably led to floristic changes (Van Riper 2005). (In an less nitrogen deficient ecosystem, this species did not have this effect.)

2. Impact on Ecological Community Structure:Moderate significance
Comments: Herb up to 250 cm in height (Weber 2003). Forms dense stands (Weber 2003) that can overtop and shade native species (WI DNR 2002).

3. Impact on Ecological Community Composition:Medium/Low significance
Comments: Displaces native species (Weber 2003). In Badlands sparse vegetation, this species acted as a nurse plant and led to increased cover of both exotic and native species (Van Riper 2005).

4. Impact on Individual Native Plant or Animal Species:Insignificant

5. Conservation Significance of the Communities and Native Species Threatened:Moderate significance
Comments: Grassland, riparian habitats and disturbed habitats (Weber 2003). Especially threatening to efforts to restore native prairies (Eckardt 1987).

Subrank II. Current Distribution and Abundance: High/Medium

6. Current Range Size in Nation:High significance
Comments: Throughout US (Kartesz 1999).

7. Proportion of Current Range Where the Species is Negatively Impacting Biodiversity:Unknown
Comments: Some sources say it is more of an aesthetic than an ecological issue (Eckardt 1987).

8. Proportion of Nation's Biogeographic Units Invaded:High significance
Comments: Potentially in all ecoregions (Kartesz 1999; TNC 2001).

9. Diversity of Habitats or Ecological Systems Invaded in Nation:Moderate significance
Comments: Grassland, riparian habitats and disturbed habitats (Weber 2003). Open disturbed habtiats, such as prairies, savannas and dunes (WI DNR 2002).

Subrank III. Trend in Distribution and Abundance: Medium/Low

10. Current Trend in Total Range within Nation:Low significance
Comments: Throughout U.S. (Kartesz 1999; Hiebert pers. comm.).

11. Proportion of Potential Range Currently Occupied:Insignificant
Comments: Throughout U.S. (Kartesz 1999).

12. Long-distance Dispersal Potential within Nation:High significance
Comments: Dispersed by water (Eckardt 1987; Weber 2003). Originally introduced for forage and honey production (WI DNR 2002).

13. Local Range Expansion or Change in Abundance:Medium/Low significance
Comments: Locally aggressive (WI DNR 2002) although it can be stable (Hiebert, pers. comm.).

14. Inherent Ability to Invade Conservation Areas and Other Native Species Habitats:Moderate significance
Comments: Grassland, riparian habitats and disturbed habitats (Weber 2003). Establishes well in grasslands following fire disturbance (Weber 2003). Can establish in the disturbed areas around fox dens and expand to a larger invasion (WI DNR 2002).

15. Similar Habitats Invaded Elsewhere:Low significance
Comments: Canada (Kartesz 1999). Also found in similiar habitats in New Zealand, South America and the British Isles (Weber 2003).

16. Reproductive Characteristics:Moderate significance
Comments: Seed bank viable for 20 years or more (Weber 2003) to 30 years (WI DNR 2002). Up to 350,000 seeds per plant (Ohio DNAP 2001).

Subrank IV. General Management Difficulty: Medium

17. General Management Difficulty:Moderate significance
Comments: Repeated cuttings of large infestions to reduce vigor; dig out scattered plants; some herbicides are effective (Weber 2003). Burning encourages germination, however burning two years in a row reduces the invasion (WI DNR 2002). Must be managed nearly continuously (WI DNR 2002).

18. Minimum Time Commitment:Moderate significance
Comments: Seed bank viable for 20 years or more (Weber 2003) to 30 years (WI DNR 2002), although, with proper burning, could be controlled in 6 years (Eckhardt 1987).

19. Impacts of Management on Native Species:Low significance
Comments: Should not need to use herbicides to manage Melilotus officinalis (WI DNR 2002). If herbicides used, can be applied before most natives emerge in the spring (Eckardt 1987).

20. Accessibility of Invaded Areas:High significance
Comments: This species will continue to be planted for it's economic/wildlife values (WI DNR 2002).

Botanical data developed by NatureServe and its network of natural heritage programs (see Local Programs), The North Carolina Botanical Garden, and other contributors and cooperators (see Sources).

  • Cole, M. 1990. Vegetation Management Guideline White and Yellow Sweet Clover (Melilotus officinalis). Illinois Department of Conservation for Illinois Nature Preserves Commission. Available ONLINE: Accessed 2002.

  • Douglas, G.W., D. Meidinger, and J. Pojar. eds. 1999. Illustrated Flora of British Columbia, Vol. 3, Dicotyledons (Diapensiaceae through Onagraceae). B.C. Minist. Environ., Lands and Parks, and B.C. Minist. For., Victoria. 423pp.

  • Eckardt. N. 1987. Element stewardship abstract for Melilotus alba, Melilotus officinalis. The Nature Conservancy, Arlington, VA.

  • 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.

  • Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.

  • Meades, S.J. & Hay, S.G; Brouillet, L. 2000. Annotated Checklist of Vascular Plants of Newfoundland and Labrador. Memorial University Botanical Gardens, St John's NF. 237pp.

  • Ohio Department of Natural Areas and Parks (DNAP). 2001. Invasive Plants of Ohio: White and Yellow Sweet-clover.

  • The Nature Conservancy. 2001. Map: TNC Ecoregions of the United States. Modification of Bailey Ecoregions. Online . Accessed May 2003.

  • Van Riper, C. 2005. The role of the exotic legume yellow sweetclover (Melilotus officinalis) in a low nitrogen system: a potential ecosystem transformer and facilitator of invasion. Unpublished dissertation, University of Minnesota.

  • Weber, E. 2003. Invasive plant species of the world: a reference guide to environmental weeds. CABI Publishing, Cambridge, Massachusetts. 548 pp.

  • Wisconsin Department of Natural Resources (WI DNR). 2002. Yellow Sweet Clover (Melilotus officinalis) White Sweet Clover (Melilotus alba). Available ONLINE: (Accessed 2002).

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