Explanation:

Alfalfa, (Medicago sativa), also called lucerne or purple medic, perennial, cloverlike, leguminous plant of the pea family (Fabaceae), widely grown primarily for hay, pasturage, and silage. Alfalfa is known for its tolerance of drought, heat, and cold and for the remarkable productivity and quality of its herbage.  The plant is also valued in soil improvement and is grown as a cover crop and as a green manure.