Flora of the Canadian Arctic Archipelago

DELTA Home

S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, L.J. Gillespie, A.K. Brysting, H. Solstad, and J.G. Harris

Epilobium arcticum Sam.

English: Fireweed.

Onagraceae, Fireweed family.

Published in Bot. Not. 1922: 260. 1922.

Type: Described from Greenland, Novaya Zemlya, Vaigach Island, and arctic Siberia.

Synonymy. Epilobium davuricum Fisch. subsp. arcticum (Sam.) P.H. Raven, Feddes Repert. 79: 61. 1968.

Vegetative morphology. Plants (2–)6–12(–17) cm high; perennial herbs. Only fibrous roots present. Ground level or underground stems absent. Caudex present (inconspicuous). Aerial stems developed; erect. Aerial stem trichomes spreading. Leaves distributed along the stems; opposite (all the way up the stem which distinguishes this taxon from E. anagallidifolium); dying annually and non-persistent. Petioles absent (short attenuate leaf bases may sometimes appear petiole-like). Leaf blade bases truncate, or attenuate. Blades 4–10 mm long, 1–3(–4) mm wide, spreading, oblong (narrow) or ovate (leaves near the base of the plant) or obovate (young leaves), flat, veins pinnate (faintly) or appearing single-veined. Blade adaxial surface glabrous. Blade abaxial surface glabrous or hairy (along the midrib), hairs puberulent, hairs sparse or moderately dense, hairs white, hairs curved. Blade margins entire or dentate (or shallowly sinuate, repand dentate), glabrous; apices obtuse, or rounded.

Reproductive morphology. Flowering stems with leaves. Flowering stems hairy. Flowering stems pubescent. Flowering stem hairs simple; shorter than the diameter of the flowering stem; white or translucent. Flowers solitary, or in inflorescences. Inflorescences racemose (if applicable); diffuse; elongating as the fruit matures. Pedicels with non-glandular hairs. Flowers per inflorescence 1–4; small (excluding length of inferior ovary), or medium-sized (including length of ovary). Sepals conventional; 4; free; 0.5–1 mm long; 3–3.5 mm wide; green and red (tinged). Calyx glabrous (most of the surface), or hairy. Calyx hairs puberulent, or pubescent; non-glandular; white or translucent. Petals conventional; free; 4; white, or pink (pale); obovate; slightly lobed or undulating; 4–4.5 mm long; 1.5–2.5 mm wide. Stamens 8; stamen filaments glabrous. Anthers 0.3–0.4 mm long. Nectaries present (rudimentary). Ovary inferior; carpels 4; syncarpous. Ovaries glabrous, or hairy; puberulent, or pubescent. Ovary hairs sparse, or very dense; white. Styles 1; 2.5–3.5 mm long; straight. Stigmas per ovary 4. Placentation axile. Ovules per ovary numerous. Fruit stalked; stalk 25–40 mm long (usually erect); without calyx persisting; dry; a capsule; elongate-cylindrical; brown, or red (tinged); 20–40 mm long; 1.2–2 mm wide; hairy (with non-glandular hairs); surface appearing veinless; not distinctly flattened; dehiscent; splitting to the base into separate segments; teeth 4. Seeds numerous; 1.2–1.4 mm long (with a tuft of silky hairs 6–7 mm long); brown; surfaces smooth, ridged (slightly).

Chromosome information. 2n = 36.

2n = about 36. Gervais et al. (1999, northeastern Canada).

Ploidy levels recorded 4x.

Ecology and habitat. Elevation 100–500 m. Substrates: wet meadows, around the margins of ponds, depressions of low-centre polygons, along streams, river terraces; imperfectly drained moist areas, seepage slopes, solifluction slopes; silt, clay, till, moss; with low organic content. Rare in wet clay tundra barrens (Porsild 1957). Open muck where water stood earlier; moist silts and clays (CAN 312087); wet flats with Aulocommium (CAN 295903); wet lake shore; stony sedge meadow; stream channel; by brook; abandoned camp; moderately drained till and bedrock, a pioneer species on a surface disturbed by camp activities (CAN 485054).

North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec. Range in the Canadian Arctic Archipelago limited. Uncommon. Arctic. Arctic islands: Baffin, Ellesmere, Axel Heiberg, Parry islands (Melville), Banks, Victoria, Prince of Wales, Southampton (Boothia and Melville peninsulas).

Northern hemisphere distribution. Circumpolar (with a gap in northern Europe). Polar Ural – Novaya Zemlya, Yamal–Gydan (?), Taimyr – Severnaya Zemlya, Kharaulakh, Yana–Kolyma, West Chukotka, Wrangel Island, East Chukotka, North Alaska – Yukon, Central Canada, Labrador – Hudson Bay, Ellesmere Land – Peary Land, West Greenland, East Greenland.

General notes. Samuelsson (1922) based the original description of this species on collections from Siberia, Novaya Zemlya, and Greenland, and provided a photograph of pressed plants to illustrate the species he was describing.

Hoch (unpublished) considers E. arcticum to be restricted to North America, in northern Alaska, NWT (especially the former Franklin Territory), Canadian Arctic Archipelago, and Greenland north of 70°N. The species was, however, originally described from "Groenlandia, Nova Zemblia, insula Waigatsch et Sibiria arctica", i.e., almost every major arctic region except for North America. Samuelsson cited and illustrated specimens from all the mentioned areas, and no specific type was indicated (Elven et al. 2003).

Illustrations. • Close-up of plant in flower. Plant with one flower. The short pedicel arising in the axil of a leaf, has a broad inferior ovary , above which the sepals and petals arise. Nunavut, Baffin Island. August 4, 1961. N.G. Smith VP-84–61. CAN 282155. • Close-up of flower. Flower with long basal pedicel, swollen inferior ovary that constricts at the apex near the base of the dark reddish sepals. Note the pale pink petals that are longer than the sepals. Nunavut, Ellesmere Island, Hot Weather Creek. 6 July, 1988. S.A. Edlund and C. Roncato-Spencer 116. CAN 532958. • Plant in fruit. Plant in fruit on a turfy hummock. Nunavut, Ellesmere Island, Lake Hazen. Plant found on the 1958 Lake Hazen 'expedition'. CMN Photo Library S85–2591. Photographer unknown. • Close-up of plants in early fruit. Plants with pedicels that are longer than the flowers, and fruiting capsules that have developed from the inferior ovaries. The sepals, petals and anthers that were attached at the top of the ovary have been shed. Nunavut, Axel Heiberg Island, Expedition Fiord. 16 July, 1962. Beschel 12903. CAN 295554. • Close-up of plants in late fruit. Left, plant with a fruiting capsule just beginning to split. Right, a capsule that has split into the 4 darker brown curving carpels, with the erect, yellowish axis of the axile placentation. The dark seeds have plumose tufts 3–4 times longer than the seeds. Nunavut, Southampton Island, Yorke Bay. 15 August, 1952. B.R. Irvine 81. CAN 261981. • Arctic Island Distribution.


This publication is available on the internet (posted May 2011) and on CD-ROM (published in 2007). These versions are identical in content, except that the errata page for CD-ROM is accessible on the main index page of the web version.

Recommended citation for the web-based version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. NRC Research Press, National Research Council of Canada, Ottawa. http://nature.ca/aaflora/data, accessed on DATE.

Recommended citation for the CD-ROM version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. [CD-ROM] NRC Research Press, National Research Council of Canada, Ottawa.

.

Contents