China is the hometown of Coptis chinensis, which is distributed in the mountainous areas from the west to the middle and east of China. The output of Rhizoma Coptidis in Sichuan accounts for 80% of the national total output, so it is customary to use "Chuanlian" in traditional Chinese medicine prescriptions.

Coptis chinensis is a perennial herb of Ranunculaceae. It grows in a cool and humid place under the alpine forest. Underground roots are long and branched, with many fibrous roots, all of which are yellow. Because the rhizome is knotty and connected in strings, it is named "Huanglian". The petiole is slender and consists of three leaflets and compound leaves. Small white flowers bloom in spring, born on the upper part of the flower stem, and 3-8 flowers form cymes, which are dioecious.

Coptis chinensis is a kind of medicine famous for its bitter taste. Because its rhizome contains an alkaloid-berberine. Someone has done an experiment: Berberine 1 serving, added with 250,000 times of water, can still taste bitter after being completely dissolved.

Rhizoma Coptidis used as medicine is cold and bitter, and has the functions of clearing away heat and dampness, purging fire and detoxifying. Traditional Chinese medicine uses it to treat diarrhea, dysentery and vomiting caused by damp-heat, excessive internal heat, restlessness and insomnia.

Modern research has proved that Coptis chinensis has a wide range of antibacterial effects. It has a strong inhibitory effect on staphylococcus and streptococcus. The antibacterial activity against Staphylococcus aureus is stronger than penicillin. Now it has been made into tablets and injections as antibacterial and anti-inflammatory drugs.