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

Symphyotrichum pygmaeum (Lindley) Brouillet and S. Selliah

English: Little aster, pygmy aster.

Asteraceae (Compositae), Daisy family.

Published in Sida 21: 1635. 2005

Type: Richardson, s.n. Arctic Coast.

Synonymy. Aster pygmaeus Lindl. ex DC., Lindl., in W.J. Hooker, Fl. Bor.-Amer. 2: 6. 1834.

Aster sibiricus L. var. pygmaeus (Lindl.) Cody, Can. Field-Natural. 68: 117. 1954.

Aster sibiricus L. subsp. pygmaeus (Lindl.) Á. Löve and D. Löve, Bot. Not. 128: 521. 1976.

Eurybia pygmaea (Lindley) G. L. Nesom, Phytologia 77(3): 261. 1994.

Vegetative morphology. Plants 4–25 cm high; perennial herbs. Only fibrous roots present. Ground level or underground stems horizontal, or vertical; rhizomatous; elongate, or compact; 1–2 mm wide. Caudex absent. Aerial stems erect. Aerial stem trichomes spreading. Leaves present; distributed along the stems; erect (or spreading); alternate; dying annually and non-persistent. Petioles absent. Leaf blade bases truncate. Blades 20–50 mm long, 4–6 mm wide, spreading, lanceolate or oblong, flat, appearing single-veined. Blade adaxial surface glabrous or hairy, hairs glandular or simple, hairs dense, hairs a mixture of white and yellow hairs (glandular hairs yellow tipped, non-glandular hairs clear and multicellular). Blade abaxial surface hairy, hairs long-silky (occasionally with glandular hairs as well), hairs sparse or moderately dense, hairs a mixture of white and yellow, hairs straight, hairs spreading. Blade margins entire, with non-glandular hairs (these long hairs widely spaced along the margins); apices acuminate, or acute.

Reproductive morphology. Flowering stems with leaves. Flowering stems hairy. Flowering stems woolly. Flowering stem hairs simple; shorter than the diameter of the flowering stem, or longer than the diameter of the flowering stem (near the capitulum); white or translucent and yellow; glandular hairs absent. Inflorescences solitary heads; terminal. Flowering heads 10–20 mm deep; 15–30 mm wide; with disc and ray florets. Involucral bracts present. Number of rows 2–3. Outer involucral bracts mostly green, or outermost bracts green, sometimes with red pigment in centre; innermost bracts frequently purple or occasionally green; lying adjacent to the flowers; lanceolate; 6–12 mm high; 0.9–1.5 mm wide; densely hairy; without glandular hairs. Inner involucral bracts linear, or lanceolate; 8–10 mm high; 0.6–1 mm wide; margins narrow and scarious, less than one quarter of the bract; apex entire (apex attenuate). Flowers bilaterally symmetrical (zygomorphic) (ray florets), or radially symmetrical (actinomorphic) (disc florets); unisexual (ray florets), or bisexual (disc florets). Sepals represented by a pappus. Pappus with a single row of hairs; yellowish (brown). Ray florets pappus 10–12 mm long. Disc florets pappus 4–8 mm long. Petals conventional; fused; 5; purple (ray florets), or yellow (disc florets); 4.5–5 mm long. Corolla tubular, or funnel-form (disc florets), or flat, strap-like (ray florets); 5-lobed (disc florets). Ray florets 15–23; limb 9–13 mm long; limb 1.7–3.2 mm wide. Stamens 5 (disc florets). Anthers yellow; 2.4–2.6 mm long. Ovary inferior; carpels 2; syncarpous. Styles 1; 8.5–10 mm long. Stigmas per ovary 2. Placentation basal. Ovules per ovary 1. Fruit sessile; with calyx persisting; dry; cypselas; oblong; 1.2–2.1 mm long; 0.3–0.7 mm wide; hairy; surface venation ribbed; indehiscent. Seeds 1.

Chromosome information. 2n = ?.

We are unaware of any records.

Ecology and habitat. Substrates: dry meadows, along streams; clay (one report).

North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, continental Nunavut. Range in the Canadian Arctic Archipelago limited. Rare. Low Arctic. Arctic islands: Banks, Victoria.

Northern hemisphere distribution. North American (American Beringian). North Alaska – Yukon, Central Canada.

General notes. This taxon is fairly distinctive and phytogeographically falls into a relictual pattern shared by several other taxa in coastal northwestern Canada and northeastern Alaska (Elven et al. 2003).

Illustrations. • Habitat. Purplish flowers growing in the left-hand foreground on a fox mound. N.W.T., Banks Island. 2003. Lynn Gillespie 7190, H. Bickerton, and L. Consaul. • Surface view of flowers. Purple flowers growing with white Stellaria on a grassy slope. N.W.T., Banks Island. 2003. Lynn Gillespie 7190, H. Bickerton and L. Consaul. • Close-up of inflorescence. Daisy-like flowers with purple ligulate florets and yellow disc florets. Note densely hairy involucral bracts seen on flowering head that are in bud. N.W.T., Banks Island. 2003. Lynn Gillespie 7190, H. Bickerton and L. Consaul. • Close-up of inflorescences. Daisy-like flowers with purple ligulate florets and yellow disc florets. N.W.T., Banks Island. 2003. Lynn Gillespie 7190, H. Bickerton, and L. Consaul. • Side view of inflorescence. Side view of inflorescence showing densely hairy involucral bracts and flowering stems. N.W.T., Banks Island. 2003. Lynn Gillespie 7190, H. Bickerton, and L. Consaul. • 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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