Flora of the Canadian Arctic Archipelago


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

Artemisia borealis Pallas subsp. borealis

English: Boreal Wormwood,

French: Armoise boréale.

Asteraceae (Compositae), Daisy family.

Published in Reise Russ. Reich. 3: 775. 1776.

Type: Western Siberia: "In rupestribus arcticae plagae, circa Obum fluvium". Holotype: BM.

Synonymy. Artemisia campestris L. subsp. borealis (Pallas) H.M. Hall and Clements, Publ. Carnegie Inst. Wash. 326: 122. 1923.

Artemisia campestris var. borealis (Pall.) M. Peck, Man. Pl. Oregon, 768. 1941.

Oligosporus borealis (Pallas) Poljakov, Trudy Inst. Bot. (Alma-Ata) 11: 167. 1961.

Artemisia campestris auct. non L., 1753.

Artemisia groenlandica Wormskjold, in Hornem., Fl. Dan. 9, 27: 10, t.1585. 1818.

Oligosporus groenlandicus ( Wormskjold) A. Löve and D. Löve, Bot. Not. 128: 521. 1976.

Artemisia borealis var. purshii Besser ex Hooker, FL. Bor.-Am. 326. 1834.

Vegetative morphology. Plants (5–)10–20(–30) cm high; perennial herbs; caespitose. Only fibrous roots present (fibrous roots from underground stems usually), or taproot present (a main vertical root from a vertical caudex). Ground level or underground stems horizontal, or vertical; rhizomatous (if applicable); elongate, or compact; 5–10 mm wide. Caudex present (sub-ligneous). Aerial stems developed; erect, or ascending. Aerial stem trichomes appressed (if applicable). Leaves heterophyllous (basal leaves pinnately dissected, cauline leaves linear); mainly basal and distributed along the stems; erect; alternate; marcescent (basal leaves). Petioles present (basal leaves), or absent (linear leaves on flowering stems); 0–60(–80) mm long (CAN 466274); winged (at the base), or not winged (near the blade); hairy; villous. Petiole hairs shorter than the diameter of the petiole; appressed; straight; smooth. Leaf blades simple. Leaf blade bases attenuate. Leaves not grass-like. Blades 6–25 mm long, (1–)10–15 mm wide (the basal leaves 0.5–10–15 mm, linear flowering stem leaves 0.5–1 mm wide), spreading, linear (flowering stems; basal leaves pinnately divided), flat, appearing single-veined. Blade adaxial surface glabrous or hairy (sparsely), hairs short-silky and long-silky, hairs simple, hairs sparse or moderately dense (young leaves), hairs white, or translucent. Blade abaxial surface hairy, hairs short-silky and long-silky, hairs sparse or moderately dense or very dense (very variable), hairs white, hairs straight, hairs appressed. Blades lobed or cut into linear divisions (basal leaves) or not lobed (flowering stem leaves). Blade margins entire or deeply divided, glabrous or with non-glandular hairs; degree of incision 90–95% (pinnately divided with (2-)3–7 divisions; these sometimes divided again); apices acute.

Reproductive morphology. Flowering stems two or more per plant; with leaves. Flowering stems hairy. Flowering stems villous, or woolly. Flowering stem hairs simple; shorter than the diameter of the flowering stem, or longer than the diameter of the flowering stem; white or translucent. Inflorescences of several flowering heads (in spicate or racemose inflorescences); terminal, or lateral (flowering stems are terminal inflorescences that have linear leaves and 1–3 heads borne on short pedicels or branches from the axils of the leaves); 5–18 cm long. Flowering heads 3.8–4.2 mm deep; 3.8–4.2 mm wide; with only disc florets. Pedicels with non-glandular hairs (sometimes almost glabrous). Bract leaves 2–15 mm long (1-several linear leaves that merge with the involucral bracts on the short pedicels). Involucral bracts present. Number of rows 2–3 (of ovate bracts). Outer involucral bracts mostly wine red or purple pigmented, or outermost bracts green, sometimes with red pigment in centre; innermost bracts frequently purple or occasionally green (with membranous margins); lying adjacent to the flowers; ovate (spatulate); 2.5–3.5 mm high; 1–2(–2.2) mm wide; glabrous (or almost so, subtending pedicels hairy), or sparsely hairy; without glandular hairs. Inner involucral bracts ovate (narrowly); 2.8–3.2 mm high; 1.1–1.4 mm wide; margins narrow and scarious, less than one quarter of the bract; apex entire (obtuse). Flowers radially symmetrical (actinomorphic). Sepals absent. Petals conventional; fused; 5; yellow, or red (at the underside of the tips of the petals so that the centre of the disc may appear read before the flowers open); with contrasting markings (petals are coloured near the tips and pale towards the base); 1–1.5 mm long. Corolla tubular, or funnel-form; 5-lobed. Stamens 5. Anthers yellow; 1–2 mm long. Ovary inferior; carpels 2; syncarpous. Styles 1; 1.5–1.7 mm long. Stigmas per ovary 2. Placentation basal. Ovules per ovary 1. Fruit sessile; dry (no material in fruit among CAN Baffin Island specimens); cypselas; indehiscent. Seeds 1.

Chromosome information. 2n = 18, or 36.

2n (2x) = 18. Erlandsson (1938, Greenland?); Böcher and Larsen (1950, Greenland); Jørgensen et al. (1958, Greenland); Sokolovskaya and Strelkova (1960, northern Russia); Sokolovskaya (1960a, northeastern Asia, Sokolovskaya; 1963 northeastern Asia, Kamtch, 1968, northeastern Asia, Koryak); Zhukova (1965a, eastern Chukotka; 1980 southern Chukotka); Hedberg (1967, northern Canada); Zhukova and Petrovsky (1976, north and northeastern Asia); Dalgaard (1988, western Greenland). Several more southern counts;

2n (4x) = 36. Johnson and Packer (1968, northwestern Alaska); Dawe and Murray, in Löve (1979, Alaska, two counts); Zhukova and Petrovsky (1980, western Chukotka); Lavrenko et al. (1989, northern Russia); Murray and Kelso (1997, western Alaska). A few more southern counts.

Ploidy levels recorded 2x and 4x.

Ecology and habitat. Substrates: along streams, river terraces, lakeshores, seashores, barrens; dry; gravel, sand. Tufts at the edge of a gravel road (CAN 466274); on a turfy ledge (CAN 2596086); weedy sand beach above high water mark (CAN 550032).

North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago widespread. Uncommon. Low Arctic (subarctic). Arctic islands: Baffin, Banks, Victoria.

Northern hemisphere distribution. Circumpolar, or circumboreal. Northern Fennoscandian, Polar Ural – Novaya Zemlya, Yamal–Gydan, Taimyr – Severnaya Zemlya, Anabar–Olenyok, Kharaulakh, Yana–Kolyma, West Chukotka, Wrangel Island, South Chukotka, East Chukotka, West Alaska, North Alaska – Yukon, Central Canada, Labrador – Hudson Bay, West Greenland.

General notes. Sect. Campestres Korobkov, Polyni Severo-Vostoka SSSR, 112. 1981.

There seems to be very few morphological differences, if any, between the diploids named by the Löves as O. groenlandicus and the tetraploids named as O. borealis. They are therefore both retained inside A. borealis s.s.

Elven et al. (2003) noted that a superficial survey of the Alaskan material (ALA) by Murray and Elven showed much, and partly geographically structured, variation. It might be possible to recognise at least three entities, a main entity throughout most of the area, a north to northwestern coastal entity comparable to 'richardsoniana', and also a southwestern coastal entity fairly distinct from the main one. All three reach the Arctic in Alaska. This variation merits further study.

Wang et al. (1990) isolated two polyacetylenes from Artemisia borealis. One exhibited antifungal (Cladosporium cucumerinum) activity and another was highly active in a brine shrimp (Artemia salina) assay and exhibited larvicidal activity against the yellow fever mosquito (Aedes aegypti).

Illustrations. • Close-up of plant. Plants with blue-green leaves, and inconspicuous, brownish inflorescences from the current and the previous season. Nunavut, Rankin Inlet. Aiken and Brysting 01–058. CAN. • Surface view of leaves. Silvery blue-green leaves of vegetative plant growing on exposed dry gravel. Nunavut, Baffin Island, Mt. Joy landing site. Aiken and Iles 02–043a. CAN. • Close-up of leaves. Blue-green, almost glabrous leaves, borne on long petioles with pinnately divided leaf blades in the upper part, and linear leaves seen at the base of the vivid reddish and almost glabrous flowering stems. Nunavut, Rankin Inlet. Aiken and Brysting 01–058. CAN. • Close-up of reddish flowering plant. Plant less than 10 cm high, coming into flower with reddish stems and reddish flowering heads. Aiken and Iles 02–043a. Scale bar in cm. • Yellow-orange inflorescence. Plant growing adjacent to the previous one. This plant had a conspicuous yellow inflorescence. Aiken and Iles 02–043a. CAN. Scale bar in cm. • Close-up of yellow-orange flowering head. Surface view of orange flowering head, composed of disc florets only. The reddish orange petals are beginning to spread to show the tips of the yellow anthers. Aiken and Iles 02–042a. CAN. • Capitulum in leaf axis. Flowering heads, capitula sessile in the axils of linear, almost glabrous leaves. The flowering stems are pubescent with short hairs. Note ring of yellow anthers in most flowers. White petals are outer flowers that have shed anthers. Nunavut, Rankin Inlet. Aiken and Brysting 01–058. CAN. • Almost glabrous capitulum. Capitulum with green, almost glabrous outer involucral bracts and reddish inner involucral bracts; neither of which have prominent membranous margins. Note the recurving petals with the reddish tips and the yellows anthers with the apiculate tips becoming exposed. There are two stigmas to the left. Nunavut, Rankin Inlet. Aiken and Brysting 01–058. CAN. • 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.