Status: Yellow Sweetclover is an introduced plant that is native to Europe and Asia; Yellow Sweetclover was introduced to North America as a forage crop.
Growth Form: Yellow Sweetclover is a forb/herb; upright (erect) and spreading near the base; plants mostly smooth, without hair (glabrous) or with stiff, straight, closely appressed hairs (strigose), plants are sweetly aromatic.
Leaves: Yellow Sweetclover has green pinnatelycompound leaves with 3 oval shaped leaflets, finely toothed.
Flower Color: Yellow Sweetclover has yellow or white pea-like flowers on elongated stems; the fruits are 1 or 2 seeded pods.
Flowering Season: May, June or July to October, May to August in California.
Elevation: Below 4,500 feet (1,372 m).
Habitat Preferences: Open disturbed areas, roadsides.
Recorded Range: Yellow Sweetclover has been introduced to most of North America, Africa and Australia. In Arizona it is found mostly in the eastern two-thirds of the state.
North America species range map for Yellow Sweetclover, Melilotus officinalis:
Click image for full size map.
U.S. Weed Information:Melilotus officinalis and Melilotus alba are listed in:
Weeds of Kentucky and adjacent states: a field guide;
Wisconsin manual of control recommendations for ecologically invasive plants;
Weeds of Nebraska and the Great Plains;
Invasive exotic pest plants in Tennessee;
Weeds of the United States and Canada;
Weeds of the West.
U.S. Invasive/Noxious Weed Information: In North America, according to Invasive.org (Invasive and Exotic Species of North America), Melilotus officinalis and synonyms is listed as an invasive species by the following authorities:
Alaska Exotic Plant Information Clearinghouse
City of Ann Arbor Michigan Parks and Recreation
Hoffman, R. & K. Kearns, Eds. 1997. Wisconsin manual of control recommendations for ecologically invasive plants. Wisconsin Dept. Natural Resources, Bureau of Endangered Resources. Madison, Wisconsin. 102pp.
Indiana Invasive Species Council - Invasive Plant List
Invasive Plant Association of Wisconsin
Invasive Plant Species of West Virginia
Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
Kentucky Exotic Pest Plant Council - Severe Threat
National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
WeedUS - Database of Plants Invading Natural Areas in the United States
West Virginia Invasive Species Strategic Plan and Volunteer Guidelines 2014
West Virginia Native Plant Society, Flora West Virginia Project, and West Virginia Curatorial Database System, September 3, 1999
Wetland Indicator: In North America Melilotus officinalis and synonyms has the following wetland designations:
Alaska, FACU;
Arid West, FACU;
Atlantic and Gulf Coastal Plain, FACU;
Caribbean, FACU;
Eastern Mountains and Piedmont, FACU;
Great Plains, FACU;
Hawaii, UPL;
Midwest, FACU;
Northcentral & Northeast, FACU;
Western Mountains, Valleys, and Coast, FACU.
FACU = Facultative Upland, usually occur in non-wetlands, but may occur in wetlands
UPL = Obligate Upland, almost never occur in wetlands
Genus Information: In North America, USDA Plants Database lists 14 species and 17 accepted taxa overall for Melilotus. Worldwide, World Flora Online includes 35 accepted species names and a further 38 scientific names of infraspecific rank for the genus. The Plant List has 25 records for Melilotus which includes sub-species.
The genus Melilotus was published in 1754 by Philip Miller, (1691-1771).
In the Southwestern United States: Arizona, California, Nevada, New Mexico, Texas and Utah each have 2introduced species. Data approximate, subject to revision.
Comments: Yellow Sweetclover is very similar in appearance to: Annual Yellow Sweet-clover (Melilotus indicus), however flowers on Yellow Sweet-clover are larger; this plant also resembles White Sweet Clover Melilotus albus which has white flowers and it also resembles Alfalfa Medicago sativa.
The earliest properly documented Yellow Sweetclover was reported in Virginia in 1739, however, Yellow Sweetclover was reportedly introduced in North America by 1664 just not identified. And the first evidence of White Sweetclover was collected in 1817 by a botanist in northern Nevada and Utah.
Importance to Wildlife, Birds and Livestock
Yellow Sweetclover, Melilotus officinalis has attractive flowers, the flowers and their seeds may be visited by hummingbirds and/or small mammals including rodents and granivorous birds in search of nectar or food.
According to the U.S.D.A., U.S. Forest Service; Fire Effects Information System, (FEIS), Yellow Sweetclover is utilized by wildlife and livestock.
It is readily consumed by large game animals such as White-tailed and Mule Deer, antelope and elk. Small mammals also consumed Yellow Sweetclover including Jackrabbits, cottontail and prairie dogs.
Game birds and song birds also utilized Yellow Sweetclover such as Sandhill cranes, Gambel's quail, sharp-tailed grouse, partridges and ring-necked pheasants. White-crowned sparrows, house finches and mourning doves.
Yellow Sweetclover is also valuable for cover for nesting and protection.
Beneficial Value to Butterflies, Honey Bees and Insects
Yellow Sweetclover, Melilotus officinalis has attractive flowers, the flowers and their plants may be visited by butterflies, moths, flies, honeybees, Native Bees and other insects in search of food and nectar.
Melilotus officinalis is favored by a large variety of insects, including native and other bees.
Melilotus officinalis, is a nectar source for;
Plebejus melissa, Karner blue butterflies
Learn more at Butterflies and Moths of North America, BAMONA.
Etymology:
The genus “Melilotus” (Melilo'tus:) is from the Greek words meli, "honey," and lotos, a leguminous plant.
The genus Melilotus was published in 1754 by Philip Miller, (1691-1771).
The species epithet “officinalis” (officina'lis:) means that it is sold as an herb, often applied to plants with real or supposed medicinal qualities.
The taxon “Melilotus officinalis” was published in 1776 by Peter (Pyotr) Simon von Pallas, (1741-1811).
Ethnobotany - Native American Ethnobotany; University of Michigan - Dearborn
Annual Yellow Sweetclover, Melilotus officinalis is used by southwestern United States indigenous peoples for such purposes as described below.
Dakota Other, Incense & Fragrance; Bunches of plants hung in the home for the fragrance.
Dakota Other, Incense & Fragrance; Grass hung in houses for the pleasant fragrance.
Iroquois Drug, Dermatological Aid; Infusion of flowers and rhizomes from another plant applied to the face for pimples and sunburn.
Iroquois Drug, Febrifuge; Infusion taken for typhoid-like fever caused by odor from killed snake.
Iroquois Other, Incense & Fragrance; Flowers used in a bouquet to perfume the house.
Jemez Food, Forage; Plant very nutritious food for horses.
Keres, Western Other, Insecticide; Plant used in beds as a bed bug repellent
Navajo, Ramah Drug, Cold Remedy; Cold infusion taken and used as lotion for colds caused by becoming chilled.
See complete listing of ethno-botanical uses at Native American Ethnobotany, University of Michigan, Dearborn.
