Prunella vulgaris is a traditional Chinese medicine, which has the function of clearing away fire and improving eyesight, and can treat redness, swelling, pain and headache. Known as "the holy medicine for clearing liver and protecting liver". Wet grass, wasteland and roadside growing in gully wetlands or on both banks of river banks are widely distributed in all parts of China, with Henan, Anhui, Jiangsu, Hunan and other provinces as the main producing areas.

The whole spike of Prunella vulgaris consists of several to 10 persistent calyx and bracts, each round has two opposite bracts, which are fan-shaped, with a pointed tail at the top, and obvious veins and white hairs on the outer surface. Each bract has 3 flowers, most of the corollas have fallen off, the calyx is 2-lipped, and there are 4 nutlets in it, which are oval and brown, with white protrusions at the top. It likes warm and humid environment. Cold-resistant and adaptable, but sandy loam with sufficient sunshine and good drainage is better. It can also be planted on dry slopes, foothills, forest-side grasslands, roadsides and fields, but it is not suitable for cultivation in low dust and waterlogging areas. It grows on slopes, grasslands, streams, roadsides and other wetlands, with an altitude of 3000 meters.

"Prunella vulgaris, hard and slightly cold. According to the book, many words can relieve depression and reduce fever, which can cure various diseases such as scrofula, damp arthralgia and night pain. It seems to clear away heat and cold. He Shu also said that qi is pure yang and liver and blood are supplemented, so there is no contradiction. It is known that although the gas is cold, it tastes pungent and pungent is scattered. Although its qi is cold and warm, clouds can replenish blood. Based on various syndromes such as heat stagnation in liver meridian, this treatment is ineffective, so it can be dissolved. If it is an internal fire, it is not suitable for treatment. "