Ageratum, a common weed of croplands belongs to family Asteraceae. It spreads rapidly and is a menace to environmentalists,
ecologists, scientists and farmers as well. Some very effective herbicides are though available still their implementation in the large-scale field is long over due. They are a threat not only to human health but to livestock as well. People exposed to Ageratum complain nausea and giddiness and its severity depends upon exposure length. However in countries like Brazil, Guiana, Madagascar, Nigeria, Sri Lanka etc. Ageratum conyzoides is also used as
medicine. The leaves of the plant cures ailments like rheumatism, diarrhea, dysentery, intestinal colic and are also used in cuts and sores. The leaves also prevents tetanus, act as styptic. The juice of stem and leaves and root juice is used as eye lotion. The petroleum ether extract of A. conyzoides inhibit activity of Staphylococcus aureus and its crude extract is used as a wound dressing material. The flowers too are useful whose crude extract exhibits anti-inflammatory activity. Essential oils of leaves are antifungal, antibacterial, whereas those extracted from twigs is anthelmenthic. Besides flavonoids, chromenes, benzofurans other constituents like terpenoids,
steroids too have been reported.