Medicago sativa, Alfalfa
Scientific Name: Medicago sativa
Common Name: Alfalfa
Also Called: Lucerne, Spanish: Alfalfa
Family: Fabaceae or Leguminosae Family
Synonyms: (Medicago tunetana)
Duration: Annual or perennial.
Size: Up to 2 feet or more.
Growth Form: Forb/herb; stems decumbent to erect, glabrous or puberulous.
Leaves: Green; compound, trifoliate, leaflets up to ½ inch long, narrowly lanceolate to obovate.
Flower Color: Purple or multicolored; flowering inflorescence spike-like with up to 25 flowers, fruit a legume.
Flowering Season: April to October
Elevation: Below 4,500 feet
Habitat Preferences: Disturbed areas, agricultural areas, roadsides.
Recorded Range: Alfalfa has found its way through most of North America, including Canada and Mexico. In Arizona it is found in the northern, central and southeast parts of the states.
North America & US County Distribution Map for Medicago sativa.
U.S. Weed Information: Medicago sativa is listed in: Weeds of the United States and Canada. Plants included here may become weedy or invasive.
Invasive/Noxious Weed Information: No information available.
Wetland Indicator: In North America Medicago sativa has the following wetland designations; Alaska, UPL; Arid West, UPL; Atlantic and Gulf Coastal Plain, UPL; Eastern Mountains and Piedmont, UPL; Great Plains, UPL; Midwest, FACU; Northcentral & Northeast, UPL Western Mountains, Valleys, and Coast, UPL.
UPL, Obligate Upland, Nonhydrophyte, Almost never occur in wetlands
FACU, Facultative Upland, Nonhydrophyte, Usually occur in non-wetlands, but may occur in wetlands.
Threatened/Endangered Information: No information available.
In the Southwestern United States: Arizona has 4 species of genus, California has 7 species, Nevada has 3 species, New Mexico has 3 species, Texas has 6 species, Utah has 3 species. All data approximate and subject to revision.
In the United States there are 2 recorded sub-species in Medicago sativa.
Medicago sativa ssp. falcata, yellow alfalfa, (throughout North America);
Medicago sativa ssp. sativa, alfalfa, (throughout North America).
3 more sub-species that may occur in North America:
Medicago sativa ssp. caerulea
Medicago sativa ssp. glomerata
Medicago sativa ssp. x tunetana
Comments: In Arizona and elsewhere Medicago has become naturalized. The plants in the photos above were taken at 2,500 feet along the road up to Mount Ord, Maricopa County, Arizona. Alfalfa is heavily utilized by wildlife including birds and mammals. It is an excellent food source for most herbivores and omnivores. It is important as a rehabilitation species of overgrazed areas.
In Southwest Desert Flora also see Burclover, Medicago polymorpha.
The genus Medicago was first published in 1753 by Carl Linnaeus.
See complete listing of ethno-botanical uses at Native American Ethnobotany, University of Michigan, Dearborn.