COMMON NAME

Hairy willow-herb
Codlins and cream
European fireweed


FULL SCIENTIFIC NAME

Epilobium hirsutum L.


FAMILY NAME COMMON

Evening primrose family


FAMILY SCIENTIFIC NAME

Epilobium hirsutum


IMAGES


Close-up of flower

Flower and fruits

Habit

Incursion

Leaves

Ripe fruit capsules with seeds

Seeds

NOMENCLATURE/SYNONYMS

Synonyms: None


DESCRIPTION

Botanical Glossary

Epilobium hirsutum is an herbaceous perennial that spreads by rhizomes. The stems are erect and softly hirsute-pubescent, measuring 0.5-2 m (1.5-6.5 ft.) in height. The leaves are opposite and lanceolate to oblong-lanceolate in shape. They are sessile, often clasping at the base. The leaves grow up to 5-12 cm (2-4.75 in.) long by 1-3 cm (0.4-1 in.) wide and have sharply serrulate margins. These leaves are pubescent on both the upper and the lower surfaces. The rose-colored flowers appear in racemes in the upper leaf axils from July to September. They are about 2.5 cm (1 in.) across and have four notched petals that are pubescent at their base. The slender fruit capsules are 5-8 cm long (2-3 in.). The seeds are oblong and flattened, measuring 1 mm (0.04 in.) long and have a tuft of long, nearly white hairs. Page References Crow & Hellquist 210, Fernald 1058, Gleason & Cronquist 316, Holmgren 297, Magee & Ahles 767, Newcomb 160, Peterson & McKenny 270. See reference section below for full citations.


SIMILAR SPECIES

Epilobium angustifolium L. (Fireweed, great willow-herb) E. angustifolium differs from E. hirsutum in that its leaves are longer, measuring 15-20 cm (6-8 in.), and it also does not have pubescent leaves.


REPRODUCTIVE/DISPERSAL MECHANISMS

Epilobium hirsutum spreads vigorously by way of rhizomes. It can also spread by wind-dispersed seeds, though this method is secondary to its vegetative reproduction.


DISTRIBUTION

Epilobium hirsutum is a native of Eurasia and North Africa. It is now found in Europe, Africa, Asia, southern Australia (as of 1990) and the United States. In the United States it is found from Maine to Wisconsin and South from Illinois to Maryland, as well as in the states of Washington and Oregon. It has been reported from all the states of New England.


HISTORY OF INTRODUCTION IN NEW ENGLAND

The earliest record of Epilobium hirsutum in the Northeast is from Newport, Rhode Island in 1829. After this date there is a gap until the 1850's and 1860's when it was reported in a number of sites along the northeastern seaboard (Stuckey, 1970). These records suggest that it may have been brought to the U.S. in ship ballast. It may have been purposefully cultivated, but soon after it became noted as a garden weed. After its arrival in coastal areas it spread inland at a fairly rapid pace.


HABITATS IN NEW ENGLAND

Edge, Herbaceous Wetland, Lake or Pond, River or Stream, Wet Meadow, Yard or Garden

Epilobium hirsutum grows in moist to wet soils and is generally found in wetland to semi-aquatic habitats. It has the ability to adapt to wet conditions through the development of arenchymal tissues in its stem and rhizomes. It prefers open conditions where it can receive ample light. Its habitat preferences and pattern of spread are similar to that of Lythrum salicaria.


THREATS

Epilobium hirsutum can form dense monotypic stands in natural wetland areas, and is capable of crowding out native species.


DOCUMENTATION NEEDS

Documentation required: A specific photograph or mounted snippet of the stem and flowers.
Best time for documentation: Summer.


ADDITIONAL INFORMATION

University of Washington Herbarium
State distribution map and images

Integrated Taxonomic Information System
Taxonomic information about the species

The PLANTS database
General information and map

BioImages- The Virtual Field Guide
Images

The Connecticut Botanical Society

Washington State Department of Ecology
Description, ecology and general information


REFERENCES

Barakat, H.H., S.A.M. Hussein, M.S. Marzouk, I. Merfort, M. Linscheid, M.A.M. Nawwar. 1997. Polyphenolic metabolites of Epilobium hirsutum. Phytochemistry 46 (5): 935-941.

Britton, N. L. and A. Brown.  1970.  An Illustrated Flora of the Northeastern United States vol. 2.  Dover Publications Inc., New York. 

Crow, G.E. and C.B. Hellquist. 2000. Aquatic and Wetland Plants of Northeastern North America. Vol #1. University of Wisconsin Press, Madison

Fernald, M.L. 1950. Gray's Manual of Botany 8th ed. American Book Co., Boston.

Gleason, H.A. and A.C. Cronquist.  1991.  Manual of Vascular Plants of the Northeastern United States and Adjacent Canada. 2nd ed.  New York Botanical Garden, Bronx, New York.

Holm, L.G., Pancho, J.V., Herberger, J.P., and Plucknett, D.L. 1979. A Geographical Atlas of World Weeds. John Wiley and Sons, New York, USA.

Holmgren, N.H. 1998. Illustrated Companion to Gleason and Cronquist's Manual.  New York Botanical Garden, Bronx, New York.

Magee, D.W and H.E. Ahles. 1999.  Flora of the Northeast. University of Massachusetts Press, Amherst.

Newcomb, N. 1977.  Newcomb's Wildflower Guide.  Little Brown, Boston.

Peterson, R.T. and M. McKenny. 1968. A field Guide to Wildflowers of Northeastern and North-central North America.  Houghton Mifflin, Boston.


Stuckey, R.L. 1970.  Distributional History of Epilobium hirsutum in North America.  Rhodora  72: 164-181.

USDA, NRCS.  2001.  The PLANTS Database, Version 3.1. (http://plants.usda.gov).  National Plant Data Center, Baton Rouge, LA 70874-4490 USA.