Rosebay Willowherb, also known as Fireweed and Great Willowherb (Chamaenerion Angustifolium [Epilobium Angustifolium]) is a perennial forb in the Willowherb or Evening Primrose Family (Onagraceae). It’s native to North America and Eurasia. Blooms Jul-Sep and grows 4-6 ft. Commonly found in meadows, prairies, savannas, and forest edges and openings. Tolerates moist to dry soils and partial shade to full sun exposure.
Rosebay Willowherb is the name commonly used in Britain. Great Willowherb is used in parts of Canada, more commonly known in North America as Fireweed. Fireweed has been moved from the Epilobium genus to the Chamaenerion (Chamerion) genus because of several distinctions from epilobiums.