A story about Golden Thread

Nothing is bitterer than Golden Thread,
Whose green leaves winter keeps spread.
Clearing plus detoxifying move sickness away,
Sweetening the bitter, love is on her way.
This is a prevailing poem in Chinese folk, telling a story that Golden thread helps a boy and a girl become a couple.
It is said that this story happened in Si Chuan province. There was a famous herbalist doctor owning a big garden where many herbal medicines are planted. As he often went out to treat diseases for other people, he hired a gardener called Huang Lian (the Chinese name of Golden Thread) to look after his herb garden. One day, this gardener discovered a kind of grass which looks like chamomile. Although it was in winter, this grass was green and in yellow flowers. The boy took this lovely plant back and transplanted it in the garden. Several days later, he caught a cold and had a sore throat. Happy in sight of the grass, he could not help picking some leaves and sucking them in mouth. He felt refreshed and his sore throat is eased unaware.
The boy was loving the beautiful daughter of the famous herbalist but he was so shy and felt unqualified to tell her his affection. One day, the girl was ill. She had unbearable fever, vomiting, diarrhea and often felt thirsty. The herbalist tried all the prescriptions he knew but her daughter’s medical condition did not turn better. The boy Huang Lian was also very worried about his beloved girl and spared no effort to help the herbalist. Suddenly, the magical flower occurred to his mind. The he told the herbalist the experience that day. After tasted the leaves of the plant himself, the herbalist thought this plant may have the functions of clearing heat, detoxifying, replenishing water and curing diahrrea. He boiled this plant with water. As expected, the fever was reduced and diahrrea was stopped. Then the girl turned better.
After this accident, the herbalist looked the boy with new eyes and the boy eventually expressed his love to the girl. They became a couple later.
As it is the boy Huang Lian who discovered this plant and its function, the herbalist named this plant as Huang Lian. In English, Huang Lian is Golden Thread. Since then, Golden Thread has been used to detoxify and cure Hiahrrea in Chinese Troditional Medicines.