Erigeron flagellaris is a North American species of flowering plants in the daisy family known by the common names trailing fleabane . Erigeron flagellaris is widespread across much of western North America. It has been found in western Canada (Alberta + British Columbia), the western United States (primarily the Rocky Mountains and Intermountain regions) and northern Mexico (from Chihuahua east to Tamaulipas and south to Durango).