Fireweed (Epilobium angustifolium L.), a native herbaceous perennial, occurs across most of Canada. It is particularly abundant on recently disturbed ground in coniferous or mixed forest ecosystems and is a common weed of roadsides and waste areas, especially in areas with acidic soils. In some successionally advanced vegetation, however, widely spaced colonies with low stem densities may persist for long periods. Where growth of the species is prolific, seedling establishment of commercially important coniferous trees can be suppressed and the species can be a problem in perennial crops.Key words: Epilobium angustifolium, fireweed, fire, forest succession, forest weeds