Flora of the Canadian Arctic Archipelago
Asteraceae (Compositae), Daisy family.
Published in In Jurtz., Fl. Arct. URSS 10: 178. 1987.
Synonymy. Artemisia richardsoniana Besser, Bull. Soc. Imp. Naturalistes Moscou 9: 67. 1836.
Oligosporus henriettae (Krasch.) Poljakov, Trudy Inst. Bot. (Alma-Ata) 11: 168. 1961.
Vegetative morphology. Plants (6–)8–15(–20) cm high; perennial herbs; caespitose. Only fibrous roots present (fibrous roots off underground stems usually), or taproot present (a main vertical root from a vertical caudex). Ground level or underground stems vertical; elongate, or compact; 2–15 mm wide. Caudex present. Aerial stems developed; erect, or ascending. Aerial stem trichomes spreading, or erect. Leaves heterophyllous (basal leaves pinnately divided; flowering stem leaves linear); mainly basal (pinnately dissected leaves), or distributed along the stems (more linear leaves); erect; alternate; marcescent (basal leaves), or dying annually and non-persistent (flowering stems). Petioles present (basal leaves), or absent (flowering stem leaves); 0–35 mm long; winged (at the base), or not winged (near the blade); hairy; villous, or woolly. Petiole hairs shorter than the diameter of the petiole, or longer than the diameter of the petiole; appressed, or spreading; straight, or curved; smooth. Leaf blade bases attenuate. Blades 6–20 mm long, 1–12 mm wide, spreading, linear (flowering stems; pinnately divided basal leaves), flat, appearing single-veined. Blade adaxial surface hairy, hairs villous and long-silky, hairs simple, hairs dense, hairs white, or translucent or tawny. Blade abaxial surface hairy, hairs villous and long-silky, hairs very dense, hairs white or rust-coloured (tawny), hairs straight or curved, hairs appressed or spreading. Blades lobed or cut into linear divisions (basal leaves) or not lobed (flowering stem leaves). Blade margins entire (flowering stem leaves) or deeply divided (basal leaves), with non-glandular hairs; degree of incision 80–95% (4–7 primary divisions and 1–4 secondary divisions); 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, or brown (a pale tawny brown). Inflorescences of several flowering heads; terminal, or lateral (flowering stems have linear leaves and 1–3 heads borne on short pedicels or branches from the axils of the leaves); 6–15 cm long. Flowering heads (3–)4–5 mm deep; 4.5–7 mm wide; with only disc florets. Pedicels with non-glandular hairs. Involucral bracts present. Number of rows 2–3. Outer involucral bracts mostly green (with a dark line down the centre; margins broadly membranous); lying adjacent to the flowers; linear, or ovate (folded or deeply spatulate); 2.5–4 mm high; (0.6–)1–2 mm wide; densely hairy; without glandular hairs. Inner involucral bracts ovate (narrowly); 2.8–3.2 mm high; 1–2 mm wide (with a dark line down the centre); margins wide, scarious for at least one quarter of the bract. Flowers radially symmetrical (actinomorphic). Sepals absent. Petals conventional; fused; 5; red, or purple; with contrasting markings (with red colouration at the tips of the petals; pale towards the base); 3–3.5 mm long (petal lobes recurved at anthesis). Corolla tubular, or funnel-form; 5-lobed. Stamens 5. Anthers yellow; 1–1.2 mm long (prominently apiculate). Ovary inferior; carpels 2; syncarpous. Styles 1; 3.4–3.8 mm long. Stigmas per ovary 2. Placentation basal. Ovules per ovary 1. Fruit sessile; dry; cypselas; ovoid; indehiscent. Seeds 1.
Chromosome information. 2n = 36, or 90.
2n (4x) = 36. Petrovsky and Zhukova (1983);
2n (10x) = 90. Johnson and Packer (1968, northwestern Alaska).
The two widely divergent ploidy levels are considered unusual.
Ploidy levels recorded 4x and 10x.
Ecology and habitat. Substrates: river terraces, tundra, barrens; moderately well-drained areas; rocks, gravel, sand; calcareous, or non-calcareous, or circum-neutral. On the tundra and the bank above the beach, Sachs Harbour (CAN 464420); silty till, marine reworked, Diamond Jenness Peninsula (CAN 489202); colonising calcareous sand-gravel bar in broad river channel at head of Minto Inlet (CAN 484769); dry stony summit rolling arid tundra (CAN 464505).
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut. Range in the Canadian Arctic Archipelago limited. Uncommon. Arctic. Arctic islands: Banks, Victoria.
Northern hemisphere distribution. Amphi-Beringian. Taimyr Severnaya Zemlya, Kharaulakh, Wrangel Island, West Alaska, North Alaska Yukon, Central Canada.
General notes. Sect. Campestres Korobkov (1981), Polyni Severo-Vostoka SSSR, 112. 1981.
Ling, in Hind and Beentje (1996), considered A. richardsoniana (and A. subarctica) as synonyms of A. arctica and not closely related to A. borealis. American authors (e.g., Cody 1996) considered A. richardsoniana a northwestern American endemic, but that was not supported by Elven et al. (2003). The Panarctic Flora Checklist (Elven et al. 2003) prefers to recognise the taxon as Artemisia borealis Pall. subsp. richardsoniana (Besser) Korobkov, in Jurtz.
Illustrations. • Habitat. Plants with silvery grey leaves near the markers growing on dry, rocky tundra. The grey colour is due to the dense cover of villous or woolly hairs on both surfaces of the leaves. Note flowering stems about 10 cm high with red capitula. The yellow green leaves are Papaver plants. N.W.T., Banks Island, Aulavik National Park. Aiken 99–031. CAN. Scale bar in cm. • Habitat. Habitat of plant in early flowering stage. N.W.T., Banks Island, Parker River valley. August, 1999. Photograph by R. Elven. Vouchers at CAN and O. • Inflorescence. Inflorescence with capitula borne in the axis of silvery grey leaves, flowering stem and linear leaves conspicuously hairy. Note lower capitula borne on pedicels, upper capitula are sessile. The yellow "dots" are clusters of five anthers for each flower, the petals are reddish. N.W.T., Banks Island, Sachs Harbour, 6 mi west of Sachs Harbour. 25 July, 1981. J.M. Gillett 18825. CAN. • Inflorescence in bud. Capitula sessile in the axils of leaves with long-silky hairs. They are composed of disc florets with red tips to the closed buds. Aiken 99–031. CAN. • Close-up of inflorescence. Almost globose capitula that are sessile in the upper part of the inflorescence, borne in the axils of linear, villous leaves. The yellow "dots" are each a ring of five conate anthers in a single flower, the petals are wine red, the involucral bracts have a dark centre, a broad membranous margin, and are covered in hairs. N.W.T., Banks Island, 6 mi west of Sachs Harbour. J.M. Gillett 18825. CAN. • Close-up of pressed inflorescence. Note petal tips dry a reddish colour. Banks Island, Sachs Harbour, 30 July, 1949. A.E. Porsild, 17531. CAN 128139. • 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..