Flora of the Canadian Arctic Archipelago

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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 tilesii Ledeb. subsp. tilesii

Asteraceae (Compositae), Daisy family.

Published in Mém. Acad. Imp. Sci. St. Pétersbourg Hist. Acad. 5: 568. 1815.

Type: Described from the Russian Far East: "In Kamtschatka", leg. Tilesius. Holotype: LE.

Synonymy. Artemisia tilesii Ledeb. var. unalaschkensis Besser, Linnaea 6: 214. 1831.

Artemisia tilesii Ledeb. subsp. unalaschkensis (Besser) Hultén, Fl. Aleut. Islands, 327. 1937.

Vegetative morphology. Plants (10–)15–35(–50) cm high; perennial herbs. Only fibrous roots present (fibrous roots off a sub-ligneous, underground "trunk"), or taproot present (a main vertical root from a vertical caudex). Ground level or underground stems horizontal, or vertical; rhizomatous; elongate; 4–15 mm wide. Caudex present (elongate or compact, unbranched or freely branched). Aerial stems developed; erect. Leaves heterophyllous (basal leaves pinnately lobed or divided; flowering stem leaves, small and linear), or not heterophyllous (inflorescence leaves easily overlooked); distributed along the stems; erect; alternate; marcescent (basal leaves), or dying annually and non-persistent (flowering stems). Petioles present, or absent; 0–10 mm long; not winged (at the base, a contrast with other Canadian Arctic species); glabrous (adaxial surface), or hairy (abaxial surface); woolly (abaxial surface). Petiole hairs shorter than the diameter of the petiole; appressed; curved; smooth. Leaf blade bases attenuate. Blades 20–80 mm long, 10–30 mm wide, spreading, lanceolate or triangular (broadly, pinnately lobed), flat, veins palmate. Blade adaxial surface glabrous. Blade abaxial surface hairy, hairs tomentose or woolly, hairs very dense, hairs white (so that the under-surface looks white or grey except for narrow green glabrous margins), hairs straight or curved, hairs appressed or spreading. Blades lobed. Blade margins dentate or deeply divided, glabrous (the adaxial blade surface slightly rolled under at the margins); degree of incision 45–90% (broadly, pinnately divided with 3–7 primary divisions); apices acute.

Reproductive morphology. Flowering stems solitary; with leaves. Flowering stems hairy. Flowering stems tomentose, or woolly. Flowering stem hairs simple; shorter than the diameter of the flowering stem; white or translucent. Inflorescences of several flowering heads; terminal, or lateral (flowering stems have linear leaves); 6–10 cm long. Flowering heads (3.5–)4–6 mm deep; (4–)5–8 mm wide; with only disc florets. Pedicels absent, or subtending flowering heads; with non-glandular hairs (tomentose; pedicels less than 5 mm). Involucral bracts present. Number of rows 2–3. Outer involucral bracts mostly wine red or purple pigmented (in the centre with a dark brown scarious margin); lying adjacent to the flowers, or spreading to erect; ovate; 3–4 mm high; (0.7–)1–2 mm wide; sparsely hairy (tomentose). Inner involucral bracts ovate (broadly); 3.5–4.2 mm high; 2.2 mm wide; margins wide, scarious for at least one quarter of the bract; apex entire, or lacerate. Flowers radially symmetrical (actinomorphic). Sepals absent (reduced to small papillae at the base of the petals). Petals conventional; fused; 5; pink (at the petal lobes), or yellow (cream at the base of the petals); without contrasting markings; 3–3.5 mm long. Corolla tubular, or funnel-form; 5-lobed. Stamens 5. Anthers yellow (with apiculate tips); 1.5–1.8 mm long. Ovary inferior; carpels 2; syncarpous. Styles 1; 4–4.5 mm long. Stigmas per ovary 2. Placentation basal. Ovules per ovary 1. Fruit sessile; dry; cypselas (no fruit found on Arctic island specimens at CAN, but collections were all made before August); indehiscent. Seeds 1.

Chromosome information. 2n = 18.

2n = 18. Sokolovskaya and Strelkova (1960); Zhukova (1965a, eastern Chukotka; 1965b, Wrangel Island; 1967a, northeastern Asia; 1980, southern Chukotka); Sokolovskaya (1968, northeastern Asia, Koryak; 1970, northeastern Russia); Johnson and Packer (1968, northwestern Alaska); Mulligan et al. (1972a); Korobkov (1972, northeastern Asia); Zhukova and Petrovsky (1975, 1976, western Chukotka); Zhukova et al. (1977, northeastern Asia); Krogulevich and Rostovtseva (1984, Siberia).

Ploidy levels recorded 2x.

Indigenous knowledge. Andre and Fehr (2000) reported that the Gwich'in people use this plant as a medicine and insect repellent. If the plant is boiled, inhaling the steam will clear nasal passages. Wormwood tea is made for colds and sore throats. Wormwood can be put on a fire to make a strong-smelling smudge that repels mosquitoes.

Ecology and habitat. Substrates: lakeshores, slopes; seepage slopes, solifluction slopes; with low organic content, with high organic content. Reported from alluvial fans (CAN 535612) and sunny alluvial slopes (CAN 331419) on Banks Island.

North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, continental Nunavut. Rare. Low Arctic. Arctic islands: Banks (two new records from Banks Island since Porsild (1957)).

Northern hemisphere distribution. Amphi-Beringian. Kanin–Pechora, 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.

General notes. Sect. Artemisia.

Porsild and Cody (1980) recognised that this taxon may be divided into subsp. tilesii and subsp. elatior Torrey and Gray. The latter has broader leaf-segments, is a taller plant, and does not occur as far north.

This widespread species seems to be polymorphic, particularly in North America. Hultén (1950, 1968b) recognised four subspecies, but two of these seem to be less distinctive than the others. The Panarctic Flora checklist (Elven et al. 2003) proposed recognising only two taxa and includes subsp. gormanii with subsp. elatior and subsp. unalaschcensis in subsp. tilesii.

Ovenden (1986) found Artemisia tilesii was an early colonising species on the lake bed of Illisarvik, the site of a thermokarst lake that was artificially drained in August 1978. By 1985, the lake bed was dry in most areas and wind erosion was extensive. The surface material was either sandy peat or organic lake mud, except along the eastern margin, where it was sandy. Substrate type appeared to have had little influence on the distributional patterns of the colonising vegetation. More important factors were probably erosion, surface wetness, and proximity of the lake-bed margin. Other widespread species included Tephroseris palustris (L.) Fourr. subsp. congesta (Senecio congestus), Carex aquatilis, Descurainia sophioides, Tripleurospermum maritimum (Matricaria ambigua), Arctophila fulva, and Stellaria longipes. Senecio and Arctophila formed dense stands around the two small residual ponds.

Adams et al. (1984) described the effects of simulated acid rain (pH 2.5–5.6) on the foliar histology of A. tilesii, which is remarkably tolerant to naturally occurring atmospheric acidity at Smoking Hills, Northwest Territories.

Adams and Hutchinson (1984) compared the ability of leaf surfaces of Artemisia tilesii, Spinacea oleracea, and Phaseolus vulgaris to neutralise acidic rain. Acidic droplets of identical size were placed on the leaves. The pH values over time were measured using a micro-pH electrode. The pH of rain droplets initially of pH 3.0, 3.5, and 5.6 increased after contact with leaves of these species. However, for droplets of pH 2.5 the pH of droplets actually decreased with time on leaves as the drops evaporated, despite the very large quantity of H ions neutralised by the leaf surface. Neutralisation of acidic droplets was greatest in A. tilesii plants, which also showed the lowest sensitivity to foliar injury from simulated acid rain. Large increases in Ca, especially, but also in Mg and K in droplets collected from leaves of A. tilesii, suggest that these cations may play an important role in increasing the pH of acidic droplets.

Hutchinson and Adams (1987) used A. tilesii in a study of the relative abilities of four species to neutralise acidic rain droplets placed on their leaf surfaces. They were examined, comparing this species with leaves of sugar beet (Beta vulgaris), radish (Aphanus sativus), and sunflower (Helianthus annuus). Rain droplets (50 mæl) of pH 4.7, 3.8, 3.0, and 2.4 were used. Determinations of droplet pH on the leaf surfaces and on a control parafilm surface were made at intervals until the leaves dried. The plants were grown in sand culture with calcium supplied at a range of five concentrations, from 4.8 to 480 ppm to alter the calcium status of the foliage. While the Ca++ treatments strongly influenced the Ca++ content of leaves, they did not influence the neutralising ability of the leaves.

Overfield et al. (1980) reported that a plant used by the southwestern Alaskan Eskimos for treatment of skin infections, chest colds, and arthritis was identified as A. tilesii. The volatile constituents of this plant were identified as an 80:20 mixture of thujone and isothujone. Isothujone has codeine-like properties, which may help arthritic pain.

Illustrations. • Habitat. Anne Brysting surrounded by plants of Artemisia tilesii while examining a Cerastium. N.W.T., Tuktoyaktuk. • Habitat. Flowering plants in a weedy habitat along a picket fence. Note the pinnately divided basal leaves and the more simple stem leaves. Alaska, Seward Pen., Nome. July, 1998. Photograph by R. Elven. No voucher. • Inflorescence. Inflorescence in full flower. Alaska, Seward Pen., Nome. July, 1998. Photograph by R. Elven. No voucher. • Close-up of leaves. Plant between the markers. Note the basal leaves are deeply divided, have a glabrous upper surface and a degree of incision from 45 to 90%. N.W.T., Tuktoyaktuk. Aiken and Brysting 01–105. CAN. Scale bar in cm. • Developing inflorescence. Inflorescence of capitula in bud, borne in the axils of leaves. Note the lower capitula borne on pedicels, the sessile upper capitula and the fused yellow petals. N.W.T., Tuktoyaktuk. Aiken and Brysting 01–105. 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.

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