General: plant height: 30-100 cm tall. Growth habit: ascending to erect perennial with a long taproot, often growing in colonies. Stems: usually several, freely branched, hairless or with fine, flat, stiff, very short hairs.
Leaves: alternate, divided into 3 leaflets, elliptic to oblanceolate, slender-tipped, 2-4 cm long, sharply toothed on upper halves, almost hairless to finely flat- short-hairy. Leaflets with short stalks, the terminal one longer. Stipules narrowly lance-shaped, entire.
Flowers: bluish-purple or rarely pink, white to yellowish-brown, about 7-11 mm long, 20-100, in short, rounded, stalked clusters, 1-3 cm long, from leaf axils. Calyx about 2/3 as long as the corolla.
Fruits: pods, many-seeded, coiled to 2-3 spirals, strongly net-veined but not prickled, 3-4 mm. long.
Disturbed or cultivated ground, along roadsides or railroads, in c. and s. parts of MT. Introduced from Europe, and spread in most of the U.S. and Canada.
Leaves and young shoots of alfalfa are edible, raw or cooked. The leaves can also be dried for later use. Very rich in vitamins, especially A, B, C and K, they are also a good source of protein. A very nutritious food in moderation, though it can trigger attacks in patients with systemic lupus erythematosus and large quantities can affect liver function and cause photosensitization. The seed is commonly used as a sprouted seed which is added to salads, used in sandwiches etc or cooked in soups. The seed is soaked in warm water for 12 hours, then kept moist in a container in a warm place to sprout. It is ready in about 4 - 6 days. The seeds can also be ground into a powder and used as a mush, or mixed with cereal flours for making a nutritionally improved bread etc. An appetite-stimulating tea is made from the leaves, and is slightly laxative.
Alfalfa leaves, either fresh or dried, have traditionally been used as a nutritive tonic to stimulate the appetite and promote weight gain. The plant has an oestrogenic action and could prove useful in treating problems related to menstruation and the menopause. Some caution is advised in the use of this plant, however. It should not be prescribed to people with auto-immune diseases such as rheumatoid arthritis. The plant has agents that promote gentle bowel movement, induce urination, check bleeding, are effective against scurvy, and are nutritive, stimulant and tonic. The expressed juice has an agent that induces vomiting and is also a pain-relieving medicine, milder than analgesic, used in the treatment of gravel. The plant is taken internally for debility in convalescence or anemia, hemorrhage, menopausal complaints, pre-menstrual tension, fibroids etc. A poultice of the heated leaves has been applied to the ear by the Costanoan Indians in the treatment of earache. The leaves can be used fresh or dried. The leaves are rich in vitamin K which is used medicinally to encourage the clotting of blood. This is valuable in the treatment of jaundice. The plant is grown commercially as a source of chlorophyll and carotene, both of which have proven health benefits. The leaves also contain the anti-oxidant tricin. The root is fever-reducing and is also prescribed in cases of highly colored urine. Extracts of the plant are antibacterial.