Parthenium hysterophorus: Weed of Pharmacological Importance F.Johnsy Mary 1* , Dr.M.Senthil Kumar 2 , K.Vignesh 3 , E. Vijaykumar 3 , G.Yadeshwaran 3 , V.Yamuna, E.Yuvalakshmi 3 1 Assistant Professor, 2 Professor & Principal, 3 Annai Veilankanni’s College of Pharmacy, Saidapet, Chennai, Tamil Nadu 600015, India. Corresponding author: F.Johnsy Mary Email : sharonangela2011@gmail.com Mob: 9677117387 Abstract Parthenium hysterophorus, often known as congers grass, is a noxious weed that is a member of the Asteraceae family of plants. Its natural habitats include the areas surrounding the Gulf of Mexico, Central America, Southern North America, the West Indies, and Central South America, among other places. Congress grass has risen to become one of the world's seven most destructive and deadly weeds, according to the World Health Organization. This invasive plant is also a significant concern in India. It is responsible for a variety of illnesses and allergies in both people and animals. Aside from that, there is some potential for this plant to be used as an insecticide, herbicide, fungicide, wood preservative, anti-amoebic, and even for medicinal purposes. If any species, particularly an invasive weed, is to be evaluated for its ability to benefit living organisms, it is necessary to have a thorough understanding of both its positive and negative impacts. As a result, this review paper is an attempt to describe the present state of knowledge regarding the hazardous and helpful effects of Parthenium hysterophorus on people and animals. INTRODUCTION Parthenium hysterophorus is a weed plant belonging to the Asteraceae family that has become invasive. This upright, short-lived plant is noted for its abundant growth and flourishing development, particularly in hot conditions, and for its short lifespan. Originally from north-east Mexico, parthenium was thought to be unique to the continent of America, but it is now found in nearly all nations throughout Asia and Europe [Bhowmik and sarkar, 2005]. A variety of names for Parthenium (Parthenium hysterophorus L.) are used in different nations, including carrot weed, white top, and the "Scourge of India." Parthenium is also known as wild feverfew, ragweed, bitter weed, and white top in the United States. The present review investigates the potential of Parthenium hysterophorus occurrences by studying the plant's habitat, distribution, biology, and chemical characteristics. Central America, Southern North America, the Gulf of Mexico, the West Indies, and central South America are among the regions where Parthenium hysterophorus is found in its natural habitat. The plant has now spread to every continent and island on the planet, including the United States. It has spread at an alarming rate throughout India and other nations on the Asian continent, including China, Bangladesh, Nepal, Pakistan, and others. In India, this Journal of University of Shanghai for Science and Technology ISSN: 1007-6735 Volume 23, Issue 10, October - 2021 Page-295