Fireweed, common name for Epilobium angustifolium, a member of a genus of herbaceous or shrubby plants of the evening primrose family (Onagraceae). Roughly 160 species of Epilobium (willow herbs) are found throughout temperate regions; 12 are native to Canada. Willow herbs have alternate or opposed leaves, and regular or slightly irregular flowers. The calyx forms a 4-part tube; the flower has 4 petals. Eight stamens surround the compound ovary; the fruit is a long, narrow capsule. Seeds are numerous and tufted at the top. The Yukon Territory adopted fireweed as its floral emblem in 1957. The flowers are arranged in an elongated cluster, situated terminally on a stem 50-200 cm long with alternate, spear-shaped leaves. The large purple, magenta or occasionally white flowers blossom from the bottom up. This species propagates quickly after forest fires (hence the name). Because it tends to overrun the area where it grows, fireweed should be grown in dry, poorish soil. It may be grown from seeds, shoots or root cuttings. See also Provincial Floral Emblems.