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Lantana (Lantana camara Linn) is a noxious weed that grows in many tropical and subtropical parts of the world. Ingestion of lantana foliage by grazing animals causes cholestasis and hepatotoxicity. Both ruminants and nonruminant animals such as guinea pigs, rabbits, and female rats are susceptible to the hepatotoxic action of lantana toxins. The hepatotoxins are pentacyclic triterpenoids called lantadenes. Molecular structure of lantadenes has been determined. Green unripe fruits of the plant are toxic to humans. Lantana spp. exert allelopathic action on the neighboring vegetation. The allelochemicals have been identified as phenolics, with umbelliferone, methylcoumarin, and salicylic acid being the most phytotoxic. In addition to phenolics, a recent report indicates lantadene A and B as more potent allelochemicals. Management of lantana toxicosis in animals is achieved by drenching with activated charcoal and supportive therapy. Recent reports on the bilirubin clearance effect of Chinese herbal tea Yin Zhi Huang (decoction of the plant Yin Chin, Artemisia capillaries, and three other herbs) or its active ingredient 6,7-dimethylesculetin, in jaundice are very exciting and warrant investigations on its, possible, ameliorative effects in lantana intoxicated animals. Research is being conducted on new drug discovery based on natural products in different parts of the lantana plant.

Ageratum has encroached upon a large expanse of land area in many parts of the world affecting crops, livestock and overall ecology. A number of chemical constituents including flavonoids, benzofurans, chromenes and terpenoids have been reported from different species of Ageratum. Various preparations of this plant are used in indigenous systems of medicine in manv countries. Chemical compounds and extracts of Ageratum have been found to possess insecticidal and insect repellent properties. This review presents a comprehensive account of the chemical constituents and biological properties of Ageratum and brings out “action‐plan” for future R&D areas for drugs, biocides, and value‐ added products.