Flatspine bur ragweed is a plant primarily native to parts of North America. In its native range, it thrives in various habitats and has adapted to diverse environmental conditions. While predominantly found within the major region of its origin, its presence as an introduced species in other locations is not widely recorded, suggesting a limited distribution beyond its native continental bounds.

Humans can be poisoned by airborne pollen from the flatspine bur ragweed plant, which is highly allergenic. Symptoms include allergic rhinitis, fever, and dermatitis. Pollen can travel long distances and affect people who breathe it in. The plant is native to many countries and common in residential areas.

Native to North America, flatspine bur ragweed is naturally present in 19 US states (mostly western) and 3 Canadian Prairie Provinces. Unlike the Common Ragweed, flatspine bur ragweed is considered a non-invasive plant but still acts weedy in its native range. It can be up to 91 cm tall and create dense colonies that are highly unpleasant to walk through due to the plant's spines. Flatspine bur ragweed is hardy and adaptable, growing well in disturbed areas including roadsides, abandoned land, wastelands, and damaged pastures. Its pollen is highly allergenic, creating issues for allergy sufferers throughout the allergy season – peak concentrations depend on location and altitude.