Any of about 200 plants that make up the genus Epilobium , of the evening primrose family, especially fireweed ( E. angustifolium ; also called great willow herb).
The young parts of some species can be cooked and eaten as potherbs. The plants are sometimes cultivated but must be carefully confined. The hairy willow herb, or codling-and-cream ( E. hirsutum ), is similar to fireweed but has hairy leaves and stalks and notched flower petals; in eastern North America it quickly establishes itself on cleared land. Rock fringe ( E. obcordatum ) is a low-growing form from the western U.S.