Photo Credit
Photo courtesy of Ben Legler, The Burke Museum of Natural History and Culture.

Alfalfa

Scientific name
Medicago sativa
Also Known As
Lucerne, Purple medick
Plant Family
Plant Group
Alfalfa is a clover-like plant with leaves in threes that are distinct because the leaflets have teeth only on the upper head of the leaflets. Alfalfa also has dense heads of purple flowers.
Identification Hints

There are many clover-like plants that have leaves in threes, similar to alfalfa. Alfalfa is distinct in having teeth just on the upper half of the leaflets and a large dense head of purple flowers. Siberian alfalfa (Medicago falcata) has yellow flowers and fruits with straight pods. Sweetclover leaves are very similar but have teeth scattered all along leaf margins.

Did You Know?

Alfalfa is the most important forage crop in the world and was first grown to feed livestock in Iran where it is native.Alfalfa sprouts, the sprouted seeds, are a popular salad and sandwich ingredient. Alfalfa is also used in re-vegetation and restoration projects since it provides food for wildlife as well as helping to improve soils. As with other members of the pea family, it is a nitrogen fixing plant which means that bacteria in its root nodules can take nitrogen from the air.

Leaves
The leaves are alternately compound (3-parted) and grow on erect stalks. The leaflets are small and narrow with teeth on the tips.
Flowers
The flowers are small, usually purple or pink (sometimes white), and found in compact, spike-like clusters. They are 5-parted and are about 0.25 to 0.50 in (0.6 to 1.2 cm) long.
Fruits
A tiny, 0.4 in (10 mm) leathery, spirally coiled pod with 6 to 8 seeds per pod.
Habitat
Alfalfa thrives in every state. It is generally found as a cultivated crop, but it has naturalized in disturbed habitats. It is found in fields, pastures, and rangelands. Alfalfa is able to grow on a variety of soils, but does best on rich, well-drained loamy soils. In some regions, alfalfa can become weedy or invasive and may displace desirable native vegetation.
Bloom Time
The leaves start to grow in spring. The flowers bloom from May to October depending on latitude and elevation.
States
AK, AL, AR, AZ, CA, CO, CT, DE, FL, GA, HI, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NV, NY, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VA, VT, WA, WI, WV, WY