In Vietnamese, the plant is called cứt lợn (meaning "pig feces") due to its growth in dirty areas.Ageratum conyzoides (billygoat-weed, chick weed, goatweed, whiteweed) is native to Tropical America, especially Brazil, and considered an invasive weed in many other regions. Herb 0.5-1 m. high, with ovate leaves 2-6 cm long, and flowers are white to mauve.
As a medicinal plant, Ageratum conyzoides has limited uses due to its toxicity. It is also an insecticide and nematicide.
Ingesting A. conyzoides can cause liver lesions and tumors. There was a mass poisoning incident in Ethiopia as a result of contamination of grain with A. conyzoides. The plant contains the pyrrolizidine alkaloids lycopsamine and echinatine.
A. conyzoides is prone to becoming a rampant environmental weed when grown outside of its natural range. It is an invasive weed in Africa, Australia, Southeast Asia and the USA. It is considered a moderate weed of rice cultivation in Asia.