Fireweed is a tall showy wildflower that grows from sea level to the subalpine zone. A colorful sight in many parts of the country, fireweed thrives in open meadows, along streams, roadsides, and forest edges. In some places, this species is so abundant that it can carpet entire meadows with brilliant pink flowers.

The name fireweed stems from its ability to colonize areas burned by fire rapidly. It was one of the first plants to appear after the eruption of Mt. St. Helens in 1980. Known as rosebay willowherb in Great Britain, fireweed quickly colonized burned ground after the bombing of London in World War II, bringing color to an otherwise grim landscape. Fireweed is the official floral emblem of the Yukon Territory in Canada.
(description from the USDA Forest Service web site)