Alfalfa in Leguminosae is a perennial herb with developed root system, and the main root is buried several meters to tens of meters deep. There are many stems and buds in the root neck, which are exposed on the ground or buried in the topsoil, and there are dozens to hundreds of neck tillers. Stems are inclined or erect, smooth and slightly square, about 100 ~ 150 cm high, with many branches. The leaves are pinnately trifoliate, the leaflets are oblong or ovoid, the top is serrated, and the middle leaves are slightly larger. Racemes are clustered, with 20 ~ 30 florets in each cluster, iris, short pedicel, 10 stamens, 1+9 stamens, forming a joint stamen tube, which is elastic; 1 pistil. The pod is spiral, with 2-4 circles, smooth surface and inconspicuous veins. Light green when young, dark brown when mature, not cracking. Each pod contains 2-9 seeds. The seeds are kidney-shaped, yellow or yellowish brown, with shiny surface, and the old seeds are darker in color; The weight of 1000 grains 1.5 ~ 2.3g, and there are about 300,000 ~ 500,000 grains per kg.

Alfalfa:

Perennial herbs. Roots are stout, stems are inclined or procumbent, 30 ~ 60 (100) cm long and multi-branched. Trifidate compound leaves, leaflets oblanceolate, obovate or oblong, with serrated upper edges. Racemes are densely clustered into heads, axillary, with yellow flowers and butterflies. The pod is slightly flat, sickle-shaped, sparsely erect, long 1 ~ 1.5 mm, covered with 2 ~ 4 seeds.