What are the功效 and effects of Peucedanum praeruptorum (Qian Hu)?
Peucedanum is the root of *Peucedanum praeruptorum* or *Peucedanum decursivum*, plants belonging to the Apiaceae family. It has various medicinal properties and effects, including lowering qi and resolving phlegm, dispersing wind-heat, relieving cough and asthma, clearing heat toxins, and soothing the liver to relieve depression. Specific details are as follows:
1. Lowering Qi and Resolving Phlegm: Peucedanum is used to treat symptoms of phlegm-heat, especially conditions involving cough, sore throat, and sticky sputum. It helps reduce the viscosity of phlegm, making it easier to expel, thereby improving breathing.

2. Dispersing Wind-Heat: Peucedanum also has the effect of dispersing wind-heat and can be used to treat cough and sore throat caused by wind-heat, particularly when accompanied by fever and throat pain.
3. Relieving Cough and Asthma: Peucedanum has antitussive and anti-asthmatic effects. It helps alleviate symptoms such as cough and shortness of breath caused by phlegm-heat, reducing inflammation and spasms in the respiratory tract.
4. Clearing Heat and Toxins: Peucedanum has certain heat-clearing and detoxifying properties and can be used to treat febrile conditions and infectious diseases, especially those associated with wind-heat patterns.
5. Soothing the Liver and Relieving Depression: In Traditional Chinese Medicine (TCM), peucedanum is sometimes used to relieve liver stagnation, particularly symptoms caused by emotional disturbances, such as headaches, dizziness, and chest tightness.

Peucedanum is typically administered in the form of decoctions, granules, or pills, with dosage and method of use determined according to specific symptoms and individual constitution. Prior to using peucedanum, it is advisable to consult a physician or licensed TCM practitioner to ensure safety and efficacy. Patients experiencing discomfort should seek medical attention promptly and receive standardized treatment under professional guidance to promote recovery.