Alfalfa is perennial herbaceous plants, belong to Leguminosae, Medicago.
Developed tap root system , main root is 3-6 meters under the soil, lateral root born rich nodule; Ternately compound leaf, lobule has short stalk, ovlid or elliptic, the top of leaf has sawtooth. Purple or light purple buttershaped, 1000-grain weight is 2.0 to 2.4g.