Fireweed is a native, erect perennial forb growing four to six feet high on smooth green stems that are usually without branching.
The leaves are alternate, on very short stalks or stalkless, linear - over 5x as long as wide, and thus resemble willow leaves hence the alternate common name of Great Willow Herb. The leaf surface is smooth with margins that are without teeth or with a few shallow indentations. An identifying characteristic of the plant is the leaf vein system where the lateral veins do not reach the edge of the leaf but instead join an outer margin loop vein. Fall color can be a brilliant pinkish-red.
The inflorescence is a long terminal cluster of individually stalked flowers - a raceme. The stem of the raceme will usually turn a light reddish color like the fall leaves.
The flowers are conspicuous, one inch wide, 4-parted, with a magenta corolla. The 4 lobes of the corolla spread widely into 4 petals that are broadest near the rounded tip and then narrow abruptly to the base. The long calyx tube forms 4 sepals that are long and narrow and appear between the petals. As the photos below show, the sepals are a darker shade of magenta. The reproductive parts consist of up to eight stamens with whitish filaments and deep magenta anthers. The pistil of the ovary has a long white style that ends in 4 lobes which reflex backwards. The entire flower structure is arranged to be borne on the end of the long calyx tube which contains the ovary at its base. Flowers open from bottom of the raceme to the top and as flowers near the top are opening, seed pods are forming under them from the earlier flowers.
The flower of Fireweed is protenandrous, meaning that the anthers of the stamens ripen first before the style opens into the 4 lobes and thus cannot receive pollen. This prevents self fertilization of the flower as a bee cannot leave pollen on the unreceptive style as it picks up pollen from the ripe anthers, rather the sticky pollen will only rub off on a receptive style by which time the the anthers of that flower have already decayed.
Seed: Flowers mature to a long thin stalked seed pod which is brown at maturity when it then splits open at the tip. The two parts of the pod curl backwards releasing to the wind numerous small seeds that have long white hair attached to catch the wind. When all the pods are open the top of the plant looks like a twisted mess. This is a plant whose seeds are long-lived and is said to frequently appear after an area is burned over, hence the common name. For germination, the small seeds require light plus at least 60 days of cold stratification.
Habitat: Fireweed is a species of the northern temperate forest zone world-wide. Fireweed prefers full sun with loamy soil and adequate moisture. It will tolerate dry soils but then will go dormant in the heat of summer. The root systems is rhizomatous, thus allowing the plant to spread vegetatively. If you have Japanese Beetles, this is a favorite plant. Daily beetle patrol can lessen the impact. In fertile soil the vegetative spreading can become uncontrollable so be careful where you plant it.
Names: Some botanists have recently tended to reclassify the Epilobium plants with large magenta flowers into the Chamerion genus - this species with the name Chamerion angustifolium (L.) Holub. USDA follows this and the University of Minnesota Herbarium has made the change, but some references may not yet show it. The name Chamerion is from the Greek chamai, meaning "low to the ground" or "dwarf" and nerion meaning "oleander", a reference to the type plant of the genus looking like a dwarf oleander. The leaves do resemble oleander. Before Linnaeus did his classification the name was already in use but spelled "Chamaenerion." The old genus Epilobium, is from two Greek words - epi meaning 'upon' and lobos, meaning 'a pod', thus 'upon the pod', which refers to the flower structure arranged to lie upon the end of the ovary which is at the base of the calyx tube. The species angustifolium is Latin for "narrow leaf".
The author names for the plant classification are: First to classify was 'L.' which refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. His work was amended by ‘Holub.’ which refers to Josef Ludwig Holub (1930-1999), Czech botanist, Professor of Botany, co-founder of the Czech Institute of Botany and whose work centered on Vascular plant taxonomy. He was the principal author of Flora of the Czech Republic and the Flora of Slovakia.
The common name of "Fireweed" comes from the belief that the plant is an early colonizer of newly burned areas. Thoreau disputes this - see his comments below the photo section along with commentary by others. "Great Willow Herb" is a reference to the willow-like leaves with the "great" added to distinguish Fireweed from other plants that are also called willowherb but are shorter such as Epilobium coloratum and Epilobium ciliatum. The other names listed above are used in the British Isles. "Fireweed" is commonly used in North America.
Comparisons: The flower color is similar to several of the native phlox species, such as Downy Phlox, Phlox pilosa L., but Phlox plants have 5 petals, not 4. Closer in comparison is the Dame's Rocket, Hesperis matronalis L., with 4-petaled pinkish flowers and just as tall. There the sepals are not visible from the face of the flower and the leaf is lance shaped with coarse teeth.
Above: Fireweed typically blooms in mid to late July but can begin in late May; the color can vary depending on amount of direct sunlight. Note in the photo how the seed pods form immediately after the flower fades, while flowers continue to open above, with flower buds forming at the top of the spike. Drawing courtesy of Kurt Stüber's Online Library.
Below: 1st photo - The darker colored sepals are visible between the wider petals. The stamens are quite exserted and the style forms 4 reflexed lobes as seen in the lower right flower. 2nd photo - The root system is rhizomatous, allowing the plant to spread vegetatively, in good rich soils it is an aggressive spreader.
Below: Leaf structure. The unique identifying part of the plant is the leaf vein system where the lateral veins do not reach the edge of the leaf but instead join an outer margin loop vein.
Below: 1st photo - A tangle of Fireweed multiple stems with seed pods opening. 2nd photo - Detail of a split open mature seed pod showing the silky hair attached to each seed which lofts the seed into the air.
Below: Fall color can be a beautiful pinkish-red.
Notes: Eloise Butler's records show that she obtained plants of Fireweed from Malden, Mass. on Sept. 4th, 1909; from Gillett's Nursery, Southwick MN on April 29, 1912 and again on Sept. 15, 1924 from Hillman, MN in "the vicinity of Sullivan Lake". Her earliest sources are explained in the paragraph below. Her records also show that she planted seeds of this species on Oct. 1, 1925 and more in 1927, '28, '30 and '32. On July 24, 1933 Martha Crone, as the new temporary curator of the Garden, planted a specimen obtained in Anoka, MN. Gertrude Cram sent seedlings of the plant to Martha Crone in August 1934. She collected these on Isle Royal. Mrs. Cram noted to Martha that "Miss Butler said nothing would ever induce it to grow for her but I thought you might like to make another attempt."(Letter to Martha Crone posted from Isle Royal, August 1934). [Perhaps Miss Butler planted in the wrong habitat - today it does well in the Upland Garden.] Martha later planted the species in 1946, '47, and '49.
Eloise Butler writes in her 1911 draft work - A Wild Botanic Garden - about her attempts to obtain this plant for the Garden. She wrote "I thought that this showy flower would have a fine effect massed in the meadow against the background of tamaracks." Her first attempt to obtain plants from Massachusetts resulted, in 1907, in the wrong plant being sent. In 1908 while visiting relatives in Massachusetts, she could not find the plant. But on the train returning to Minneapolis she reports there was a train "wreck" near Mackay Ontario and the whole day was spent waiting for repairs. Looking out the train window she spotted Fireweed, and promptly collected a bunch in her suitcase. She later discovered another source beyond White Bear Lake, MN. [Read her entire report]
Fireweed is native to about two thirds of the state north and east of a diagonal line from Winona County in the SE to Polk in the NW with several metro counties excepted. Two varieties are recognized as present in the state, var. angustifolium and var. canescens but the DNR does not distinguish between them on its county checklist and the U of M reports that the former was only known from Mahnomen County. In North America, Fireweed is found in most places except the very far north and the states of the U.S. bordering the Gulf of Mexico.
Lore and Uses: It is an international plant with a number of folk and herbal uses. It was used as a tea substitute in England and Russia and said to make a quite tasty tea; the French Canadians (where they called it 'asperge') liked the young flower stalks and leaves as salad ingredients (Fernald Ref. #6); fireweed honey is said to be very prized by the honey people.
As to medicinal use, Densmore (Ref. #5) reports that the Ojibwa (Chippewa) used a poultice of leaves (dry or fresh) to put on bruises. The same might be used to remove a sliver. Others report than an infusion could be made of roots and leaves to treat asthma and a heavy cough. A poultice of moistened fresh or dried leaves were applied to bites of poisonous reptiles.
Tilford (Ref. #39) reports that the young leaves and shoots which contain large amounts of vitamin C and beta-carotene are quite palatable either raw or cooked. Mature plants are tough and bitter.
Thoreau wrote about the plants commonly named "fireweed" (Epilobium angustifolium and Erechtites hieraciifolius, also called Burnweed): "However those are not with very peculiar fitness called fireweeds for they spring up in the same manner on new land when it is laid bare by whatever cause, hereabouts as often after a cutting as after a burning, though I will not deny that the ashes may be a good manure for them. Their localities with us are recently cleared, gravelly, and bare spots in sproutlands. There are enough of these seed in the air always ready to fall on and vegetate in such places."
Paleo-archaeologist Mary Leakey wrote that upon returning to London from Kenya after the Blitz and the War there were unfilled craters and uncleared rubble everywhere. "Later in the year  we saw some of the devastated areas in the city become pink with flowering spikes of willow-herb, which had colonized the open spaces and was by now well established and thriving there."(Ref.: Disclosing the Past - An Autobiography, 1984, Doubleday.
Mrs. Grieve (Ref. #7) also notes that the plant would spring up in a town, self-sown, on waste ground recently cleared of centuries old buildings. She specifically mentions areas in London around Aldwych and Westminister where old buildings were torn down and the ground remained in a wasted state for some time, though no one could explain where the seeds came from.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"