White mustard seed, also known as hot mustard seed, is the dried mature seeds of the annual or biennial plant white mustard. This stout, robust herb, ranging in height from 40-120cm, flowers in April-June and fruits in May-July. It belongs to the Cruciferae family and its entire appearance is a small round ball with a grayish-white and vaguely yellowish surface. The seed coat of white mustard is thin, brittle and oily. There is no irritating odor when asked, but the taste is pungent. This plant can be used as medicine, which is also recorded in the Compendium of Materia Medica, and is mainly used for cold phlegm, asthma and cough, chest and hypochondriac pain, phlegm stagnation of the meridians and other diseases, or for numbness and pain in the joints, which also has a relatively good therapeutic effect. It is mainly produced in Anhui, Henan, Sichuan, Shandong and other places, and after experimental cultivation, it is now distributed throughout the country. This medicine can also be made on your own, remove the impurities from the white mustard seeds, put them in a pot and fry them until they are deep yellow, and smell the aroma wafting out.