rubra), while great willowherb (Epilobium hirsutum) is found in mesotrophic grassland with stinging nettle (Urtica dioica). These two willowherb species also dominate open habitat early in ecological succession, to the virtual exclusion of other plant life. Broad-leaved willowherb (Epilobium montanum) is found characteristically, though not abundantly, in the mesotrophic grasslands with meadowsweet (Filipendula ulmaria) and sometimes the uncommon Greek valerian (Polemonium caeruleum). Most willowherbs will not tolerate shade trees and thus are limited to more recently disturbed patches, yielding to other plants over time. Consequently, though the genus contains many pioneer plants, rather few of them are invasive weeds of major importance.Epilobium species are used as food plants by the caterpillars of certain Lepidoptera species, including: Geometridae Grey pug (Eupithecia subfuscata), recorded on several species Noctuidae Mouse moth (Amphipyra tragopoginis), recorded on several species Small angle shades (Euplexia lucipara), recorded on several species Australian grapevine moth (Phalaenoides glycinae), recorded on fringed willowherb (E. ciliatum) Sphingidae Elephant hawk-moth (Deilephila elpenor), recorded on several species Small elephant hawk-moth (Deilephila porcellus), recorded on several species White-lined sphinx (Hyles lineata), recorded on several species Use by humans The main use of Epilobium by humans is as a herbal supplement in the treatment of prostate, bladder (incontinence) and hormone disorders. Many of the small willowherb species are nuisance weeds in gardens. Though few are regularly used as ornamental plants, the larger willowherbs may be attractive in ruderal locales. One of the most frequently recognized members of the genus is the circumboreal fireweed (E. angustifolium), known as rosebay willowherb in the United Kingdom. It rapidly colonizes burnt ground; during the bombing of London in World War II many of the derelict bomb sites were soon covered with these plants, bringing a splash of colour to what was otherwise a very grim scene. It is the floral emblem of Yukon in Canada, Hedmark in Norway (where it is called geitrams) and Southern Ostrobothnia in Finland. Fireweed is used as a sweetener in northwestern North America. It is put in candy, jellies, ice cream, syrup, and sxusem ("Indian ice cream"). In the late summer its flowers yield pollen and copious nectar which give a rich spicy honey. Its young leaves, roots, and shoots are edible (if somewhat bitter), and rich in provitamin A and vitamin C. The Dena’ina found them also useful as food supplement for dogs and applied sap from the stem to wounds, believing it to