False ragweed (Parthenium hysterophorus), also known as parthenium weed, is an invasive plant species native to the Americas but now found in many parts of the world. It belongs to the Asteraceae family and is a significant allergen due to its highly potent airborne pollen. The plant typically blooms in late summer and fall, releasing pollen that can cause allergic rhinitis, asthma, and contact dermatitis in sensitive individuals. Inhalant allergy tests often include false ragweed because of its growing prevalence and strong allergenic properties.
It can cause sneezing, a runny nose, itchy or watery eyes, respiratory discomfort, and in some cases, skin rashes or eczema due to contact sensitivity.
It typically pollinates from late summer through fall, depending on the regional climate and growing conditions.
Although both belong to the Asteraceae family and have allergenic potential, they are different species. However, cross-reactivity can occur in sensitive individuals.