It is southern alfalfa that still blooms small yellow flowers in May. Because the flowering period of southern alfalfa is from March to May, it is southern alfalfa that still blooms small yellow flowers in May. Southern alfalfa has small yellow flowers, so it is also called "golden cauliflower". The flowering period is from March to May, and the fruit period is from May to June. The seeds are kidney-shaped, brown and smooth. The whole plant can be used as medicine, and has the effects of clearing heat, promoting diuresis, relieving stranguria and removing calculus.