It is also called citronella because of its lemon fragrance. It belongs to Gramineae and is a perennial herb. It not only has ornamental value, but also can green and beautify the home. Because it contains citral, it has the efficacy of disinfection, sterilization, treatment of neuralgia and muscle pain, so it is called "pain-relieving swordsman". The recently published book "The Health Function of Tea" says that using it to make tea can improve the digestive function, strengthen the stomach and reduce fat, relieve the pain of bones and muscles, abdominal cramps or spasms, and deal with digestive problems; It can also be used to treat diarrhea, cold, fever and headache. In addition, it also has diuretic, anemia-preventing and moisturizing effects on women, and is an indispensable medicine for women's beauty care. Its side effect is that citronella is too fragrant and should not be used by pregnant women.