Cao Guo is a perennial herb of the ginger family, alias: grass fruit kernel, grass fruit seeds. The fruit is used as medicine.

Cao Guo contains volatile oil about 3% to 4%, in addition, also contains starch and oil, etc.. Volatile oil contains 1,8-eudesmol, a-serpentene anti-Muscarinol, anti-S-enal, camphor, sanguinarine, turpentine-4-ol, cinnamic acid methyl ester, nerolidol, linalool, geraniol, grass ketone, dill aikenone, acetic acid lobster oil, cardamom and so on, which is the main pungent constituent of the grass fruit of anti-S-enal. Grass berries are warm and pungent in nature; they have the functions of drying dampness and removing cold, expelling phlegm and intercepting malaria, eliminating food and resolving accumulation; they are used for cold and dampness internal obstruction, epigastric distension and pain, plumping and vomiting, and malaria, cold and heat, etc. They are also commonly used as flavoring in cooking. It is also a commonly used spice for cooking.

Mainly produced in Yunnan Wenshan, Guangxi Jingxi, Guizhou Luodian and other places.