Invasive Species: Melilotus officinalis, Yellow Sweetclover
Yellow sweetclover is an invasive annual to short-lived perennial herb native to Eurasia. Plants can grow to approximately 6.5 ft. (2 m) in height and can sometimes be woody at the base. Leaves are ovate to oblong, entire, stipulate, and 0.4 to 1 in. (1 to 2.5 cm) long. Flowering occurs from April to September, when yellow, pea-like flowers develop in a branched inflorescence at the tips of the flowering stems. Flowers are less than 0.25 in. (7 mm) long. Fruits are small, circular, wrinkled, and light brown pods that contain one seed (rarely two ). Plants occur along roadsides, in open fields, pastures, and other disturbed areas. Yellow sweet clover was introduced into North America as a forage crop in the 1900s.
What are invasive species and why should we be concerned about them?
Taxonomy: Scientific and Common Names for This Species
Fabales > Fabaceae > Melilotus officinalis (L.) Lam.
Synonym(s): yellow sweet-clover
Melilotus officinalis – USDA PLANTS Profile
Distribution Maps
Yellow sweetclover – The reported distribution of this invasive species across the United States (Source: Invasive Plant Atlas of the United States)
Up-to-the-minute distribution maps and why they are important
Reporting This Invasive Species
What is the best way and place to report the occurrence of an invasive species?
How to report an invasive species sighting to EDDMapS – Early Detection & Distribution Mapping System
EDDMapS – Report an invasive species to EDDMapS.
Cooperative Extension Offices – Find your local Cooperative Extension office on this map provided by USDA.
How to Identify
This invasive species can be identified by looking for the characteristics described in the paragraphs that follow.
Plant
Yellow sweetclover is an annual to short-lived perennial herb that can grow to approximately 6.5 ft. (2 m) in height and can sometimes be woody at the base.
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| Dave Powell, USDA Forest service, bugwood.org | Steve Dewey, Utah State University, bugwood.org |
Foliage
Leaves are ovate to oblong, entire, stipulate, and 0.4 to 1 in. (1 to 2.5 cm) long.
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| Steve Dewey, Utah State University, bugwood.org | Mary Ellen (Mel) Harte, bugwood.org |
Flower
Flowering occurs from April to September, when yellow, pea-like flowers develop in a branched inflorescence at the tips of the flowering stems. Flowers are less than 0.25 in. (7 mm) long.
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| Mary Ellen (Mel) Harte, bugwood.org | Karan A. Rawlins, University of Georgia, bugwood.org |
Fruit
Fruits are small, circular, wrinkled, and light brown pods that contain one seed (rarely two).
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| Steve Dewey, Utah State University, bugwood.org | Steve Hurst, USDA NRCS PLANTS Database, bugwood.org |
Native Species That Can Resemble Yellow Sweetclover
– Images at invasive.org
| bugwood.org | bugwood.org |
– Images at invasive.org
| bugwood.org | bugwood.org |
Additional Images for Yellow Sweetclover
Yellow sweetclover – Images at Invasive.org
Additional Information, Biology, Control and Management Resources
Control and management recommendations vary according to individual circumstances. Location, habitat, weather, and a variety of other conditions are factors that help determine the best treatment choice. To find the safest and most effective treatment for your situation, consult your state’s land-grant institution. If you will use chemicals as part of the control process, always refer to the product label.
United States Land-Grant University System – Find your land-grant university’s college of agriculture, Cooperative Extension office, or other related partner on this map provided by USDA.
Element Stewardship Abstract – The Nature Conservancy
Weed of the Week – USDA Forest Service
Terrestrial Invasives – Wisconsin Department of Natural Resources
Invasives Database – TexasInvasives.org
Species Bios – National Park Service