There is mustard seed in traditional Chinese medicine, which was first recorded in the famous doctor's Bielu, which is divided into white mustard seed and yellow mustard seed. White mustard seed, also known as spicy rapeseed, bitter mustard seed, white mustard seed, etc. Is the seed of mustard seed, a cruciferous plant, mainly produced in Shanxi, Shandong, Anhui, Sichuan and other provinces. "Materia Medica" said: "White mustard seed, pungent and warm lung, produces well in the north." "North China, Northeast China and other northern regions are used as medicines, using white mustard seeds. Its nature is warm and pungent, and it enters the lung and stomach meridians. People's Republic of China (PRC) Pharmacopoeia (20 10 edition) states that its main functions are warming lung, resolving phlegm, benefiting qi, dispersing stagnation, dredging collaterals and relieving pain, and it is used for cough due to cold phlegm, chest pain, phlegm blocking meridians, joint numbness and pain, phlegm warming and qi circulation, yin gangrene and toxic swelling.

Yellow mustard rapeseed is a mature seed of mustard seed, which is hot, pungent and slightly toxic. It enters the stomach and lung channels. Huadong is used as medicine, and its effect is similar to that of white mustard seed, but its expectorant and antiasthmatic effect is better than that of yellow mustard seed. If it is to be used instead of white mustard seed, more dosage should be used.

Trait recognition

White mustard seed is spherical, with a diameter of 1.5 ~ 2.5 mm, and its surface is grayish white or yellowish and smooth. Observing under a magnifying glass, you can see a fine network structure. There is a round hazelnut navel at one end, which swells in water. After peeling off the seed coat, you can see two full cotyledons, which are oily and folded vertically, and the radicle is wrapped inside. Slight gas, spicy taste, red tongue, after crushing and wetting, it has a particularly pungent smell and is very spicy.

Yellow mustard seed is spherical, with a diameter of 1~2 mm, yellow to brownish yellow surface, and a few are dark reddish brown, with fine reticular and punctate hilum. The seed coat is thin and brittle, and the cotyledons are wrinkled and oily. The gas is weak, and after grinding and wetting with water, it will produce pungent odor.

Microscopic identification

Cross-section of white mustard seed: the outermost surface is 1 row of tangentially elongated epidermal mucus cells, and its outer wall is specialized into mucus layer; Lower epidermis 1~2 rows of cells, thin-walled; 1 row grid element, its inner wall and side wall are thickened at 1/2, and its outer wall is thinner; Pigment cells are decadent. The endosperm is 1 row of square or rectangular cells, with fuzzy powder inside and rotten cell layer below. Cotyledons are well developed, and there are fuzzy powder particles and oil droplets in the cells.

Cross section of yellow mustard seed: 1 expels epidermal cells and extends tangentially; The subepithelial cells are 1 row, nearly square or radially elongated, about 20 microns wide, with thickened inner and outer walls and thinner outer walls; Next to the grid cell layer is the pigment layer. The endosperm is 1 row of rectangular cells with fuzzy powder inside and rotten cell layer below. Cotyledon and radicle cells contain fat oil droplets and aleurone particles.

To sum up, white mustard seed and yellow mustard seed are different in efficacy and appearance, so we should pay attention to the differences when using them. (Han Decheng)