Chamaenerion angustifolium, commonly known in North America as fireweed, in some parts of Canada as great willowherb, and in Britain as rosebay willowherb, is a perennial herbaceous plant in the willowherb family Onagraceae. It is also known by the synonyms Chamerion angustifolium and Epilobium angustifolium. is often abundant in wet calcareous to slightly acidic soils in open fields, pastures, disturbed ground, and particularly burned-over lands. As a pioneer species, it’s one of the first plants to return after forest fires in woodland clearings and is a successful coloniser.
As quite a tall fireweed plant creating tall spires of pink flowers, it can grow to around 1.5 metres. Chamaenerion augustifolium produces plenty of flowers and is great for garden butterflies, garden moths, and pollinators.