Santa Maria feverfew (Parthenium hysterophorus) - Parthenium - Invasive weed

Santa Maria feverfew (Parthenium hysterophorus), also known as carrot weed, whitetop weed, famine weed, or congress grass, is native to tropical America and is a highly invasive weed that poses a significant threat to the Indian ecosystem and human health. It is introduced to India in the 1950s through seed shipments. Its aggressive growth and allelopathic properties (releasing chemicals that inhibit the growth of other plants) are leading to reduced crop yields and biodiversity loss. Additionally, Parthenium is a known allergen, causing contact dermatitis and respiratory issues in humans and livestock. Santa Maria feverfew plants are bearing flowers in a locality at Tehatta, West Bengal, India, on May 11, 2025. (Footage by Soumyabrata Roy/NurPhoto via Getty Images)