Epilobium Angust1-4

''Epilobium'' is a genus of flowering plants in the family Onagraceae. The genus has a worldwide distribution. It is most prevalent in the subarctic, temperate and subantarctic regions, whereas in the subtropics and tropics ''Epilobium'' species are restricted to the cool montane biomes, such as the New Guinea Highlands.

The taxonomy of the genus has varied between different botanists, but the modern trend is to include the previously recognised genera ''Boisduvalia, Pyrogennema'' and ''Zauschneria'' within ''Epilobium''. ''Chamaenerion'', (previously ''Chamerion''), is considered distinct, however,Wagner & Hoch 009a,b/ref> according to Peter H. Raven, who has extensively studied the willowherbs and merges the other segregate genera into ''Epilobium''. Fringed willowherb (''Epilobium ciliatum'') is likely a cryptic species complex; apparently these plants also commonly hybridize with their congeners.

Most species are known by the common name willowherbs for their willow-like leaves. Those that were once separated in ''Boisduvalia'' are called spike-primroses or boisduvalias. Those ''Epilobium'' species previously placed in the ''Chamaenerion'' group and known as fireweeds are now segregated into the genus ''Chamaenerion''.

Description

Epilobiums are mostly herbaceous plants, either annual or perennial; a few are subshrubs. The leaves are opposite or rarely whorled, simple and ovate to lanceolate in shape. The flowers are actinomorphic (radially symmetrical) with four petals that may be notched. These are usually smallish and pink in most species, but red, orange or yellow in a few. The fruit is a slender cylindrical capsule containing numerous seeds embedded in fine, soft silky fluff which disperses the seeds very effectively in the wind.

The genus name derives from the Greek words "epi" meaning "upon" and "lobos" meaning "lobe", with reference to position of the petals above the ovary.

A number of ''Epilobium'' species with slightly asymmetrical (zygomorphic) magenta flowers and alternate leaves were placed in a ''Chamaenerion'' group, and have been separated by some authorities into the genus ''Chamerion''. However, ''Chamerion'' has not been universally accepted and there is now emerging consensus that this group of species should be segregated into the genus ''Chamaenerion''.

Habitat and ecology

Willowherbs ''sensu lato'' are typically very quick to carpet large swathes of ground and may become key or dominant species of local ecosystems. In the United Kingdom, for example, rosebay willowherb (''Chamaenerion angustifolium'') is widely found on mesotrophic soils dominated by false oat-grass (''Arrhenatherum elatius''), cock's-foot grass (''Dactylis glomerata''), and red fescue (''Festuca 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 have antiinflammatory properties.

Several researchers have studied this taxon. Heinrich Carl Haussknecht in the late 19th century and Peter H. Raven about a century later researched the phylogeny, systematics, and taxonomy of willowherbs. Peter Michaelis' studies of this genus paved the way for understanding of extranuclear inheritance in plants.

Species

The National Museum of Natural History recognizes an intermediate number of about 197 species in 10 sections, and consider the former section ''Chamaenerion'' (=''Chamerion''), as a distinct genus. Other sources may list one or two dozen species, more or less:

Section ''Boisduvalia''
* '' Epilobium densiflorum'' – denseflower willowherb, dense spike-primrose, dense boisduvalia
* '' Epilobium pallidum'' – largeflower spike-primrose
* '' Epilobium pygmaeum''''Epilobium pygmaeum''.
USDA PLANTS. – pygmy willowherb, smooth boisduvalia
* '' Epilobium subdentatum''
* '' Epilobium torreyi'' – Torrey's willowherb, brook spike-primrose

Section ''Cordylophorum''
:Subsection ''Nuttalia''
* '' Epilobium suffruticosum'' – shrubby willowherb
:Subsection ''Petrolobium''
* '' Epilobium nevadense'' – Nevada willowherb
* '' Epilobium nivium'' – Snow Mountain willowherb

Section ''Crossostigma''
* '' Epilobium foliosum'' – leafy willowherb, California willowherb
* '' Epilobium minutum'' – chaparral willowherb, desert willowherb, smallflower willowherb

Section ''Epilobiopsis''
* '' Epilobium campestre''
* '' Epilobium cleistogamum'' – selfing willowherb

Section ''Macrocarpa''
* '' Epilobium rigidum'' – stiff willowherb, Siskiyou Mountains willowherb

Section ''Xerolobium''
* '' Epilobium brachycarpum'' – tall willowherb, tall annual willowherb, tall fireweed, panicled willowherb
Section ''Zauschneria''

* '' Epilobium canum'' – Zauschneria, California-fuchsia, hummingbird flower, hummingbird trumpet
* '' Epilobium septentrionale'' – northern willowherb, Humboldt County fuchsia

Section ''Epilobium''
* '' Epilobium aitchisonii''
* '' Epilobium algidum''
* '' Epilobium alpinum''
* '' Epilobium alpestre''
* '' Epilobium alsinifolium'' – chickweed willowherb
* '' Epilobium alsinoides''
** ''Epilobium alsinoides'' ssp. ''alsinoides''
** ''Epilobium alsinoides'' ssp. ''atriplicifolium''
** ''Epilobium alsinoides'' ssp. ''tenuipes''
* '' Epilobium amurense''
** ''Epilobium amurense'' ssp. ''amurense''
** ''Epilobium amurense'' ssp. ''cephalostigma''
* '' Epilobium anagallidifolium'' – alpine willowherb, pimpernel willowherb
* '' Epilobium anatolicum''
** ''Epilobium anatolicum'' ssp. ''anatolicum''
** ''Epilobium anatolicum'' ssp. ''prionophyllum''
* '' Epilobium angustum''
* '' Epilobium arcticum'' – Arctic willowherb
* '' Epilobium astonii''
* '' Epilobium atlanticum''
* '' Epilobium australe''
* '' Epilobium barbeyanum''
* '' Epilobium billardierianum'' – glabrous willowherb
** ''Epilobium billardierianum'' ssp. ''billardierianum''
** ''Epilobium billardierianum'' ssp. ''cinereum''
** ''Epilobium billardierianum'' ssp. ''hydrophilum''
** ''Epilobium billardierianum'' ssp. ''intermedium''
* '' Epilobium blinii''
* '' Epilobium brevifolium''
** ''Epilobium brevifolium'' ssp. ''brevifolium''
** ''Epilobium brevifolium'' ssp. ''trichoneurum''
* '' Epilobium brevipes''
* '' Epilobium brevisquamatum''
* '' Epilobium brunnescens'' – New Zealand willowherb
** ''Epilobium brunnescens'' ssp. ''beaugleholei''
** ''Epilobium brunnescens'' ssp. ''brunnescens''
** ''Epilobium brunnescens'' ssp. ''minutiflorum''
* '' Epilobium capense''
* '' Epilobium chionanthum''
* '' Epilobium chitralense''
* '' Epilobium chlorifolium''
* ''Epilobium ciliatum'' – fringed willowherb, American willowherb
* '' Epilobium clarkeanum''
* '' Epilobium clavatum'' – talus willowherb, clavatefruit willowherb
* '' Epilobium collinum''
* '' Epilobium coloratum'' – purpleleaf willowherb
* '' Epilobium confertifolium''
* '' Epilobium confusum''
* '' Epilobium conjungens''
* '' Epilobium crassum''
* '' Epilobium curtisiae''
* '' Epilobium cylindricum''
* '' Epilobium davuricum'' – Daurian willowherb
* '' Epilobium densifolium''
* '' Epilobium denticulatum''
* '' Epilobium detzneranum''
* '' Epilobium duriaei''
* '' Epilobium fangii''
* '' Epilobium fastigiatoramosum''
* '' Epilobium fauriei''
* '' Epilobium forbesii''
* '' Epilobium fragile''
* '' Epilobium frigidum''
* '' Epilobium fugitivum''
* '' Epilobium gemmascens''
* '' Epilobium glabellum'' – smooth spike-primrose
* '' Epilobium glaberrimum'' – glaucous willowherb
* '' Epilobium glaciale''
* '' Epilobium glaucum''
* '' Epilobium gouldii''
* '' Epilobium gracilipes''
* '' Epilobium griffithianum''
* '' Epilobium gunnianum''
* '' Epilobium halleanum'' – glandular willowherb
* '' Epilobium hectorii''
* ''Epilobium hirsutum'' – great willowherb, great hairy willowherb, hairy willowherb, codlins-and-cream, apple-pie, cherry-pie
* '' Epilobium hirtigerum''
* '' Epilobium hohuanense''
* '' Epilobium hooglandii''
* '' Epilobium hornemannii'' – Hornemann's willowherb
** ''Epilobium hornemannii'' ssp. ''behringianum''
** ''Epilobium hornemannii'' ssp. ''hornemannii''
* '' Epilobium howellii'' – Yuba Pass willowherb, subalpine fireweed
* '' Epilobium indicum''
* '' Epilobium insulare''
* '' Epilobium kermodei''
* '' Epilobium keysseri''
* '' Epilobium kingdonii''
* '' Epilobium komarovianum'' – bronzy willowherb
* '' Epilobium lactiflorum'' – milkflower willowherb, whiteflower willowherb
* '' Epilobium lanceolatum'' – spear-leaved willowherb
* '' Epilobium laxum''
* '' Epilobium leiophyllum''
* '' Epilobium leptocarpum'' – slenderfruit willowherb
* '' Epilobium leptophyllum'' – bog willowherb, linear-leaved willowherb
* '' Epilobium luteum'' – yellow willowherb
* '' Epilobium macropus''
* '' Epilobium margaretiae''
* '' Epilobium matthewsii''
* '' Epilobium maysillesii''
* '' Epilobium melanocaulon''
* '' Epilobium microphyllum''
* '' Epilobium minutiflorum''
* '' Epilobium mirabile'' – Olympic Mountain willowherb
* '' Epilobium montanum'' – broad-leaved willowherb
* '' Epilobium nankotaizanense'' – Nankotaizan willowherb
* '' Epilobium nerteroides''
* '' Epilobium nivale''
* '' Epilobium nummulariifolium''
* '' Epilobium nutans''
* '' Epilobium obcordatum'' – rockfringe willowherb
* '' Epilobium obscurum'' – dwarf willowherb, short-fruited willowherb
* '' Epilobium oreganum'' – Grants Pass willowherb, Oregon fireweed
* '' Epilobium oregonense'' – Oregon willowherb
* '' Epilobium pallidiflorum''
* '' Epilobium palustre'' – marsh willowherb
* '' Epilobium pannosum''
* '' Epilobium parviflorum'' – small-flowered willowherb, hoary willowherb
* '' Epilobium pedicellare''
* '' Epilobium pedunculare'' – rockery willowherb
* '' Epilobium pengii''
* '' Epilobium pernitens''
* '' Epilobium perpusillum''
* '' Epilobium petraeum''
* '' Epilobium pictum''
* '' Epilobium platystigmatosum''
* '' Epilobium ponticum''
* '' Epilobium porphyrium''
* '' Epilobium prostratum''
* '' Epilobium psilotum''
* '' Epilobium pubens''
* '' Epilobium puberulum''
* '' Epilobium purpuratum''
* '' Epilobium pycnostachyum''
* '' Epilobium pyrricholophum''
* '' Epilobium rechingeri''
* '' Epilobium rhynchospermum''
* '' Epilobium roseum'' – pale willowherb
** ''Epilobium roseum'' ssp. ''consimile''
** ''Epilobium roseum'' ssp. ''roseum''
** ''Epilobium roseum'' ssp. ''subsessile''
* '' Epilobium rostratum''
* '' Epilobium rotundifolium''
* '' Epilobium royleanum''
* '' Epilobium rupicolum''
* '' Epilobium salignum''
* '' Epilobium sarmentaceum''
* '' Epilobium saximontanum'' – Rocky Mountain willowherb
* '' Epilobium sikkimense''
* '' Epilobium sinense''
* '' Epilobium siskiyouense'' – Siskiyou willowherb, Siskiyou fireweed
* '' Epilobium smithii''
* '' Epilobium staintonii''
* '' Epilobium stereophyllum''
* '' Epilobium stracheyanum''
* '' Epilobium strictum'' – downy willowherb, stiff spike-primrose
* '' Epilobium subalgidum''
* '' Epilobium subcoriaceum''
* '' Epilobium subnivale''
* '' Epilobium taiwanianum''
* '' Epilobium tasmanicum''
* '' Epilobium tetragonum'' – square-stemmed willowherb
** ''Epilobium tetragonum'' ssp. ''lamyi''
** ''Epilobium tetragonum'' ssp. ''tetragonum''
** ''Epilobium tetragonum'' ssp. ''tournefortii''
* '' Epilobium tianschanicum''
* '' Epilobium tibetanum''
* '' Epilobium trichophyllum''
* '' Epilobium vernonicum''
* '' Epilobium wallichianum''
* '' Epilobium warakense''
* '' Epilobium wattianum''
* '' Epilobium williamsii''
* '' Epilobium willisii''
* '' Epilobium wilsonii''
* '' Epilobium × wisconsinense'' – Wisconsin willowherb (=''E. ciliatum'' ssp. ''ciliatum'' × ''E. coloratum'')

former ''Chamaenerion'' group

The following species are now segregated into the genus ''Chamaenerion'' Ség. The generic name ''Chamaenerion'' is preferred to ''Chamerion''.)

Section ''Chamaenerion''
* ''Epilobium angustifolium''
* '' Epilobium conspersum''
* '' Epilobium latifolium''
* '' Epilobium speciosum''

Section ''Rosmarinifolium''
* '' Epilobium colchicum''
* '' Epilobium dodonaei''
* '' Epilobium fleischeri''
* '' Epilobium stevenii''

Formerly placed here

* '' Stylidium tenellum'' (as ''E. tonkinense'')

It is possible to distinguish between leaves of different ''Epilobium'' species using high-accuracy FT-IR method based on attenuated total reflection (ATR) without time-consuming preparation.Krajšek, S., Buh, P., Zega, A., Kreft, S. (2008). Identification of herbarium whole-leaf samples of ''Epilobium'' species by ATR-IR spectroscopy. Chemistry & Biodiversity, 5:310-31
http://onlinelibrary.wiley.com/doi/10.1002/cbdv.200890028/abstract;jsessionid=46F30B7C6B30DADFBD57A4789993E047.f01t02
/ref>

Footnotes

References

* Bleeker, Walter; Schmitz, Ulf & Ristow, Michael (2007): Interspecific hybridisation between alien and native plant species in Germany and its consequences for native biodiversity. ''Biological Conservation'' 137 (2): 248-253. (HTML abstract, appendix reserved for subscribers)
* Steenkamp, V; Gouws, M.C; Gulumian, M; Elgorashi, E.E. & van Stade, J. (2006): Studies on antibacterial, anti-inflammatory and antioxidant activity of herbal remedies used in the treatment of benign prostatic hyperplasia and prostatitis. ''Journal of Ethnopharmacology'' 103 (1): 71–75.
PDF fulltext
*
*
* Wagner, W.L. & Hoch, P.C. 009b Evening Primrose Family website &ndash
''Epilobium''
Retrieved 2009-JAN-26.

{{Taxonbar, from=Q157637

Onagraceae genera
Taxa named by Carl Linnaeus