Bidens pilosa, also known as mozote, is a wild plant classified as a weed because it invades land and often displaces other useful plants.
It's a plant of South American origin and is little used in Mexico. It's occasionally used to relieve kidney and bladder congestion, and to reduce fever and stomach inflammation by boiling its stems and leaves. In other countries, such as Cuba, the infusion is used to clear tonsillitis from the throat and to kill the bacteria that cause gastritis.
However, as far as I know, I don't recall it being used for any other purpose than as animal feed in rural areas. Dried, it can be used to make improvised brooms and mop heads, to insulate some surfaces, etc. Photographs taken in Puebla City, Mexico.
