Flora of the Canadian Arctic Archipelago
Asteraceae (Compositae), Daisy family.
Published in Folia Geobot. Phytotax. 8, 2: 173. 1973.
Type: Described from Arctic Canada: "Barren Grounds from Point Lake to the Arctic Sea."
Synonymy. Cineraria frigida Richardson, in Franklin, Bot. App. 748. 1823.
Senecio frigidus (Richardson), Less., Linnaea 6: 289. 1831.
Senecio atropurpureus (Ledeb.) B. Fedtsch. subsp. frigidus (Richardson) Hultén, Acta Univ. Lund., n. f., avd. 2, 46, 1: 1605. 1952.
Tephroseris atropurpurea (Ledeb.) Holub subsp. frigida (Richardson) Á. Löve and D. Löve, Bot. Not. 128: 520.1976.
Vegetative morphology. Plants (4–)10–40(–60) cm high; perennial herbs. Only fibrous roots present. Ground level or underground stems horizontal; rhizomatous; elongate, or compact (sometimes long and narrow); 1–3 mm wide. Caudex absent. Aerial stems erect. Aerial stem trichomes appressed, or spreading. Leaves present; heterophyllous (with or without petioles), or not heterophyllous (similar in shape); mainly basal and distributed along the stems; erect (or spreading); alternate; dying annually and non-persistent. Petioles present (basal leaves), or absent; 0–30 mm long; glabrous. Leaf blades simple. Leaf blade bases truncate, or rounded. Blades (8–)15–30 mm long, 3–13 mm wide, spreading (basal leaves) or appressed to the stem (stem leaves), circular or lanceolate or ovate (basal leaf blades circular or ovate; stem leaf blades ovate or lanceolate), flat, with three main veins (midvein often with red pigment). Blade adaxial surface without sessile glands, glabrous or hairy, hairs woolly, hairs simple, hairs moderately dense, hairs white, or translucent. Blade abaxial surface glabrous or hairy, hairs woolly (if applicable), hairs sparse or moderately dense or very dense (sparse at the base of the flowering stem increasing to dense near the capitulum), hairs white (sometimes slightly reddish; see image library), hairs straight, hairs appressed or spreading. Blade apices acute, or obtuse.
Reproductive morphology. Flowering stems solitary; with leaves; woolly (if applicable). Flowering stem hairs simple; white or translucent. Inflorescences solitary heads. Flowering heads (10–)15–20 mm deep; 20–35(–40) mm wide; with only disc florets (heads without ray florets occur occasionally), or with disc and ray florets. Pedicels absent. Involucral bracts present. Number of rows 1 (with limited overlapping of bracts). Outer involucral bracts mostly green (tips and edges can be dark and red pigmented); lying adjacent to the flowers; lanceolate, or obovate; 4–6 mm high (free portion); 1–2(–2.3) mm wide; sparsely hairy (free portion of the bracts; densely hairy on the receptacle of the capitulum with fine white hairs mixed with long clear hairs that have red cross-walls or red cell contents); without glandular hairs. Flowers radially symmetrical (actinomorphic) (disc florets), or bilaterally symmetrical (zygomorphic) (ray florets; if these are present); unisexual (ray florets, if present, female), or bisexual (disc florets). Sepals represented by a pappus. Pappus with a double row of hairs; whitish. Ray florets pappus 1.5–3.5 mm long. Disc florets pappus 1.5–3.5 mm long. Petals conventional; fused; 5; yellow; 3–6.5 mm long (tips recurving as the stigmas become receptive). Corolla flat, strap-like (ray florets), or tubular, or funnel-form (disc florets); 5-lobed (disc florets). Ray florets 7–14 (when present); limb 6–20 mm long; limb 1.3–3 mm wide. Stamens 5. Anthers yellow; 2–2.5 mm long. Ovary inferior; carpels 2; syncarpous. Styles 1; 5–5.5 mm long. Stigmas per ovary 2. Placentation basal. Ovules per ovary 1. Fruit sessile; with calyx persisting; dry; cypselas; oblong; 1.8–3.5 mm long; 0.5–0.8 mm wide; surface venation ribbed (longitudinally); indehiscent. Seeds 1.
Chromosome information. 2n = 48, or 80, or 96.
48 (6x). Zhukova and Tikhonova (1971 Chukotka); Zhukova (1982, northeastern Asia); probably also Johnson and Packer (1968, northwestern Alaska, as Senecio atropurpureus);
80 (10x). Zhukova et al. (1973, northeastern Asia, 2n = about 80).
96 (12x). Zhukova et al. (1973, northeastern Asia); Zhukova (1982, northeastern Asia); probably also Packer and McPherson (1974, northern Alaska, as Senecio atropurpureus).
Ploidy levels recorded 4x and 12x.
Ecology and habitat. Elevation 100–150 m. Substrates: wet meadows, around the margins of ponds, marshes, along streams; imperfectly drained moist areas (a wetland species, often on peat, and always associated with marsh species. It is one of the few beauties in the otherwise fairly dull wet sedge meadows on, e.g., Banks Island); silt, clay, till.
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut. Range in the Canadian Arctic Archipelago moderate. Uncommon. Arctic (limited western distribution). Arctic islands: Banks, Victoria.
Northern hemisphere distribution. Amphi-Beringian. West Chukotka, Wrangel Island, South Chukotka, East Chukotka, West Alaska, North Alaska Yukon, Central Canada.
General notes. Elven (personal communication, 2005) commented that this is another intricate aggregate, in which most of the entities seem at one time or another to have been considered as races of Senecio atropurpureus. It is closely related to T. atropurpurea (Ledeb.) Holub and T. subfrigida (Kom.) Holub, and recognition of these three as three subspecies of one species is defensible. The species name 'atropurpurea' (1815) has priority before the name 'frigida' (1823).
Burt (2000) stated that this species has a scattered growth habit, and seems to prefer heath tundra that is neither too wet nor too dry, such as protected areas where snow likely collects fairly early in the winter.
Illustrations. • Close-up of plant. Plant in bud. Note the entire shiny green leaf and involucral bracts that are reddish and have glandular hairs. N.W.T., Banks Island, Aulavik National Park, Thomsen River Valley. 7 July, 1999. Aiken 99–020. CAN. • Close-up of bud. Bud with dark coloured and hairy involucral bracts. N.W.T., Banks Island, Aulavik National Park, Thomsen River Valley. 7 July, 1999. Aiken 99–020. CAN. • Close-up of flowering plant. Plant, less than 10 cm high, with a single flowering head composed of yellow ray and disc florets. N.W.T., Banks Island, Aulavik National Park, Thomsen River Valley. 7 July, 1999. Aiken 99–020. CAN. Scale bar in cm. • 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..