Chamerion angustifolium (L.) Holub
Yukon Fireweed.
Onagraceae, fireweed family.
Folia Geobot. Phytotax. 7: 86. 1972.
Epilobium angustifolium L. Sp. Pl. 347. 1753.
Chamaenerion angustifolium (L.) Scop. nom. illegit., Fl. Carniol., ed. 2, 1: 271. 1772.
Chamerion spicatum (Lam.) S.F. Gray
Epilobium angustifolium
var. intermedium (Lange) Fernald
Vegetative morphology. Plants perennial herbs; 20–40 cm high (to 100 cm tall on continental North America); coarse, with glabrous stems that have numerous leaves. Caudex absent. Ground-level or under-ground stems horizontal; rhizomatous; elongate (in old plants), or compact; 4–6 mm wide. Aerial stems erect (stiffly); glabrous (old growth), or densely hairy (new growth); stem hairs spreading, or reflexed (if applicable). Leaves distributed along the stems; alternate; simple; existing for a single season or less. Petioles present, or absent; 0–2 mm long (if applicable); glabrous. Leaf blade bases obtuse, or acute. Blades 25–75(–90) mm long; 2–15(–18) mm wide. Blades spreading; linear, or lanceolate; flat; veins pinnate. Blades adaxial surface glabrous, or glabrescent. Blades adaxial surface hairs simple, unbranched. Blades abaxial surface hairy. Blades abaxial surface hairs sparse. Blades abaxial surface puberulent. Blades abaxial surface hairs white, or translucent hairs; curved. Blade margins entire. Leaf apices acuminate.
Reproductive morphology. Flowering stems present. Flowering stems with leaves; glabrous (glabrescent), or hairy. Flowering stem hairs puberulent (if applicable); simple; shorter than the diameter of the flowering stem; white or translucent. Inflorescence racemose; diffuse. Pedicels present; with non-glandular hairs (densely tomentose). Flowers per inflorescence 8–20 (to 80 in the Yukon); medium-sized, 5–15 mm in diameter or length, or large, more than 15 mm in diameter or length. Calyx sepals 4; free; 4–15 mm long; 1.5–2.5 mm wide. Calyx purple; hairy; pubescent (conspicuously so on the buds). Calyx hairs non-glandular; white or translucent. Petals free; 4; white (rarely), or pink, or purple (paler than the sepals, fading bluish purple); spatulate; unlobed; 10–20 mm long; 3–13 mm wide. Stamens 8; filaments glabrous. Anthers 1.7–2.2 mm long. Nectaries present (but not very conspicuous). Gynoecia inferior. Carpels syncarpous; 4. Ovaries hairy; tomentose. Ovary hairs dense; white, or translucent. Styles 1; 8–12 mm long. Styles straight; basal portion with hairs at the base. Stigmas per style 4; strap-like lobes; lobes 4–5 mm long. Ovules numerous. Fruit stalked; stalk 5–10 mm long. Fruit dry; a capsule; elongate-cylindrical; not distinctly flattened; dehiscent; splitting to the base into separate segments; teeth 4. Fruit 30–50 mm long; 10–25 mm wide; straw coloured (or greyish); hairy; surface appearing veinless. Seeds numerous (as many as 500 per fruit); 0.8–1.4 mm long; yellowish; with surfaces smooth (apex with silky tufts of hairs to 10 mm long).
Chromosome information. 2n = 36. Löve and Löve (1948 northern Europe,1956b Iceland, 1982a arctic Canada); Böcher and Larsen (1950 Greenland); Sorsa (1962 Finland); Lövkvist in Weimarck (1963 Sweden); Mosquin (1963, 1966 Canada, USA, numerous counts, 1967); Laane (1965, 1969a Norway); Knaben and Engelskjøn (1967 Norway); Johnson and Packer (1968 northwestern Alaska ); Taylor and Mulligan (1968 western Canada); Sokolovskaya (1970 north eastern Russia); Zhukova et al. (1977a north eastern Asia); Dawe and Murray (1981a western Alaska); Uotila and Pellinen (1985 Finland); Dalgaard (1989 western Greenlandl); Lövkvist and Hultgård (1999 southern Sweden). Very numerous more southern counts. Ploidy levels recorded 4x.
Distribution. Northern hemisphere distribution: circumpolar; Greenland, Canada, United States, Eurasia. Alaska, Yukon, Continental Northwest Territories, Nunavut Islands, Continental Nunavut, Northern Québec. Alpine, or low arctic (rarely). Range in the Canadian Arctic Archipelago limited (widespread on Continental North America). Arctic Islands: Baffin (south-east).
Ecology and habitat. Substrates: cliffs (gull cliffs and ledges opposite Pangnirtung); dry; rocks, gravel. Habitats: occasional on south facing screes.
Indigenous knowledge. People have used fireweed as food, for example
the young shoots consumed as greens, the leaves used to make tea, the petals
made into jelly, and the roots eaten as a vegetable (Small and Catling 1999).
Anderson (1939) noted that in Alaska young shoots of this fireweed are
gathered and boiled, usually mixed with Rumex. If bacon is added, the
dish was said to be delicious.
Andre and Fehr (2000) reported that Gwich'in
know that the whole plants can be boiled as a medicine and the liquid rubbed on
the skin for rashes. A poultice is made from the leaves and applied to burns,
bee stings, aches and swelling caused by arthritis. The pink flowers are edible
and can be mixed in with jello and salads. The new shoots can be cooked like
asparagus, chopped and eaten as greens, or mixed with salads.
Notes. The Yukon territorial flower.
A specimen collected from the
Gull cliffs opposite Pangnirtung (CAN 223779) on 15 August, 1953 by V.C.
Wynne-Edwards was determined as Epilobium angustifolium L. x E.
latifolium L. by A.E. Porsild. On the label is the note, "both parent
species and every gradation of hybrid, in profusion on manured ground beneath
the gull cliff opposite Pangnirtung Post. C. latifolium was already
finished flowering. E. angustifolium only in bud, and the hybrids make a
great show of colour." Peter C. Hoch, Missouri Botanical Garden, annotated the
specimen in 1979 as E. angustifolium subsp. angustifolium. The
observed difference in flowering time would make hybridization less likely.
Mosquin (1966) studied the taxonomy (of what he called Epilobium
angustifolium), because three chromosomal races with n =18, 36, and
54 had been discovered (Mulligan 1957 and Mosquin 1963) and he wished to
establish the way in which chromosomal discontinuity correlated with
morphological discontinuities. Mosquin recognized subspecies
angustifolium n =18 and 54, and subspecies circumvagum
Mosquin, n = 36, the later based on Chamaenerion angustifolium
var. platyphyllum Daniels. The best characters for distinguishing the
taxa are the pubescence, or lack of it, on the abaxial leaf midribs, the leaf
width, and length, whether the pollen is triporate, or a mixture of pore sizes,
and the diameter of the pollen. Mosquin (1966) mapped the distribution of 95
chromosome records; a map that indicates that plants with 2n = 36 are not
found as far north as 60°N.
Mosquin (1966) stated that white-flowered
forms are generally most common in 2n = 18 plants, less common in
2n = 36 plants and apparently unknowNorth Americaong 2n = 54
plants.
Mosquin and Small (1971) considered that C. angustifolium and
C. latifolium represent an example of parallel evolution and that
although the two species are closely related, evidence indicates that they are
isolated by ecological and genetic barriers. They admitted that F1 hybrids have
been collected from transition habitats (Böcher, 1962) but noted that
hybrids are extremely infrequent in view of the occurrence of widespread areas
of sympatry. Attempts to cross the two species gave variable results (Pugsley,
1960) but generally revealed strong barriers to F1 seed production coupled with
marked F1 pollen sterility. While these barriers were not considered
sufficiently well-developed to have prevented introgression between the two
species, Mosquin and Small (1971) stated that there was no indication of this in
the polyploids, which closely resembled their diploid progenitors, and did not
possess characters attributable to introgression from their sister species.
Evidence for parallelism was presented from five observations:
(1) Both
species occupy comparably widespread ranges in the northern hemisphere.
(2)
In each species diploids occupy the more northern and/or alpine areas with
polyploids occurring in more southern and/or warmer regions.
(3) In each
species autopolyploidy has been the mechanism of polyploidization.
(4) Each
species has retained the capacity to form high levels of quadrivalents at
meiosis, unlike many other autopolyploids (Morrison and Rajhathy, 1960).
(5)
Within each species the diploids very closely resemble the polyploids.
However, the evolution of polyploidy has been accompanied by a common
morphological change, namely an increase in frequency of extra pores in the
pollen grains.
Despite the ‘weed’ in fireweed, this species is not
usually a significant weed. Potential problems for forest managers may exist
since C. angustifolium seedlings can compete with conifer seedlings in
re-vegetating burned land, and C. angustifolium serves as the alternative
host of conifer rusts. Fireweed has also been observed to be a weed of some
vegetable crops in northern regions (Small and Catling 1999).
Inbreeding
depression (reduced fitness following self-fertilization) is extreme in
fireweed, making cross-pollination very important. Individual flowers mature
their pollen before the stigma is receptive, to prevent selfing. Bees,
bumblebees, moths, and butterflies are important pollinators of fireweed. They
characteristically move from the bottom towards the top of the flowering stem.
The insects first deposit pollen on the lower flowers, which have receptive
stigmas but anthers without pollen that was released earlier. Then, they acquire
pollen from the upper flowers, which have not yet exposed their stigmas. (Small
and Catling 1999, Galen and Plowright 1985, Husband and Schemske 1995).
A
fruit of fireweed can contain as many as 500 seeds, and a single plant may
produced as many as 80,000 seeds per year (Small and Catling 1999). The plumose
seeds can be carried by wind for hundred of kilometers (Solbreack, and Andersson
1987). A Swedish study revealed that up to half of the seed produced disperses
over the landscape more than 100 m above the ground. Humidity expands the
diameter of the seed hairs, decreasing loft, an adaptation that tends to deposit
the seeds in humid areas and during wet periods. The seeds are non-dormant and
short-lived, rarely remaining viable for more than 3 years and generally
germinating as soon as a suitable site is found.
Although seeds account for
the remarkable ability of fireweed to colonize new areas, once a seed
germinates, vegetative reproduction by rhizome becomes more important than
sexual reproduction. Fragmenting the rhizomes stimulates production of shoots
contributing to the reputation of fireweed as a hard to eradicate weed. Most of
the rhizomes occur in the top 5 cm of mineral soils, and this underground
portion can survive relatively intense fires. The above ground shoots of older
plants are killed by frost, but the plants over-winter as rhizomes (Small and
Catling 1999). Fireweed sprouted quickly from surviving rhizomes following the
volcanic eruption of Mount St Helens, Washington in 1980. One year after the
explosion 81% of all seedlings present were from fireweed.
Fireweed is not
considered toxic. Healing antiseptic compounds, such as a novel flavonoid with
strong anti-inflammatory effects, myricetin 3-O-ß-D-glucuonide, has been
found in the foliage. This active principle reaches its maximum concentration
during and shortly after the plants flower (Ducrey et al. 1995).
It has been
suggested that mutations from the radiation near uranium deposits results in a
relatively high frequency of white-flowered variants of fireweed, and that this
phenomenon can be used to find uranium (Shacklette 1964).
This species was
found to be an early colonizer of oil spills in Alaska (Kershaw and Kershaw
1986).
Illustrations. • Habitat. Relatively short plants about 25 cm high, and with few flowers, growing in dry gravel, with little organic content and often becoming very warm on days with temperatures near 30°C. Churchill, Manitoba, Aiken and Brysting 01–003. • Habitat. Taller plant, with many more flowers, growing in shrubby tundra, with more organic content in the soil and probably more moisture. Churchill, Manitoba, Aiken and Brysting 01–003. • Close-up of inflorescence. Top of the inflorescence, a raceme, showing open flowers at the base and developing buds at the top. Each flower has an inferior ovary at the top of a pedicel. Churchill, Manitoba, Aiken and Brysting 01–003. • Close-up of inforescence. Lowest flower has 4 red-pink sepals, 4 paler pink petals, pinkish, withered stamens and a whitish, fully expaned style with four stigma lobes. Upper flowers have reddish pre-anthesis anthers on white filaments, and no evidence of the style that does not elongate until the pollen have been shed. Churchill, Manitoba, Aiken and Brysting 01–003. CAN. • Close-up of flower. Close-up of a pre-anthesis flower with four thin red-pink sepals, four broad purple-pink petals, and eight developing stamens with red anthers and white filaments. The style does not elongate until after the pollen is shed and the anthers wither. Churchill, Manitoba, Aiken and Brysting 01–003. • Close-up of flower. Flower in which the first whorl of four anthers is shedding pollen, and the second whorl of anthers is still pre-anthesis. The whitish, re-cruved style is beginning to expand between the anthers. Note the narrow base of the petals. Churchill, Manitoba, Aiken and Brysting 01–003. • Close-up of flower. Close-up of lower flowers with four free linear-lanceolate, reddish pink sepals, obovate free petals that from a narrow base old anthers that have shriveled and fully elongated style with four receptive stigma lobes. Churchill, Manitoba, Aiken and Brysting 01–003. • Close-up of rhizome. Rhizome of a large and vigorous plant from Yukon, Ogilvie Mts., river flats along Dempster Rd. 30 July 1966. R.T. Porsild 371. CAN 303679. • Arctic Island Distribution.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
