Flora of the Canadian Arctic Archipelago
| Flora of the Canadian Arctic Archipelago | |
English: Mastodon flower, marsh ragwort,
French: Séneçon des marais.
Asteraceae (Compositae), Daisy family.
Published in Folia Geobot. Phytotax. 9(3): 272. 1974.
Type: Canada: Melville Island.
Synonymy. Cineraria congesta R. Br., Chloris Melvill. 21. 1823.
Senecio congestus (R. Br.) Hooker, Fl. Bor.-Am. I. 334. 1834.
Senecio arcticus Rupr., Fl. Samojed. Cisural. 44. 1845.
Senecio congestus R.Br. f. polycriocs Polunin, Bull. Natl. Mus. Canada 94 (Biol. Ser. 24): 367. 1940.
Vegetative morphology. Plants (4–)10–25(–60) cm high; annual herbs, or biennial herbs (under certain conditions). Only fibrous roots present. Ground level or underground stems absent. Caudex absent. Aerial stems erect (stems hollow). Aerial stem trichomes spreading. Leaves heterophyllous (basal leaves often narrow with toothed margins; flowering stem leaves wider with entire margins); mainly basal (plant less than 10 cm high), or distributed along the stems (plants more than 20 cm high); erect (or spreading); alternate; dying annually and non-persistent. Petioles absent (long attenuated leaf blade bases may appear petiole-like). Leaf blades simple. Leaf blade bases attenuate. Blades 1.5–15 mm long, 1–20(–27) mm wide, spreading, linear or lanceolate or obovate (basal leaves linear or lanceolate; stems leaves lanceolate or ovate), flat, appearing single-veined. Blade adaxial surface glabrous (basal leaves) or hairy (leaves near the inflorescence), hairs puberulent or pubescent or pilose (very variable), hairs simple, hairs sparse or moderately dense or dense, hairs white, or translucent or tawny. Blade abaxial surface glabrous or glabrescent or hairy (sometimes with hairs on the midvein), hairs woolly, hairs sparse or moderately dense or very dense, hairs white or rust-coloured (from colour at the end walls of the multicellular, floccose hairs), hairs wavy, hairs appressed or spreading. Blade margins entire (upper leaves) or dentate or runcinate (larger lower leaves), glabrous (lower leaves) or with non-glandular hairs (leaves near the inflorescence), with 0–6 teeth on each side of the blade, with teeth toward the apex (rarely on the lower half of the blade); degree of incision 1–60%; apices acuminate, or acute, or rounded.
Reproductive morphology. Flowering stems with leaves; woolly. Flowering stem hairs simple; shorter than the diameter of the flowering stem; white or translucent, or brown (from colour in the end walls of multicellular, floccose hairs); glandular hairs absent. Inflorescences of several flowering heads. Flowering heads 8–20 mm deep; 12–20 mm wide; with disc and ray florets. Pedicels subtending flowering heads; with non-glandular hairs. Involucral bracts present. Number of rows 1–2. Outer involucral bracts mostly green, or mostly wine red or purple pigmented; lying adjacent to the flowers; oblong, or lanceolate; 2.5–5.5 mm high; 0.5–0.7 mm wide (excluding long marginal hairs); sparsely hairy, or densely hairy; without glandular hairs. Inner involucral bracts linear, or lanceolate; 2.5–5.5 mm high; 0.5–0.7 mm wide; margins wide, scarious for at least one quarter of the bract; apex entire (with long hairs). Flowers radially symmetrical (actinomorphic) (disc florets), or bilaterally symmetrical (zygomorphic) (ray florets); bisexual (both ray florets and disc florets). Sepals represented by a pappus. Pappus with a single row of hairs; whitish. Ray florets pappus (2.5–)4–12(–15) mm long. Disc florets pappus (2.5–)4–8(–12) mm long. Petals conventional; fused; 5; yellow; 5.5–8 mm long. Corolla tubular, or funnel-form (disc florets), or flat, strap-like (ray florets); 2-lobed to 3-lobed (ray florets), or 5-lobed (disc florets). Ray florets 12–20; limb 3.5–7 mm long; limb 0.5–1.5 mm wide. Stamens 5. Anthers yellow; 1.4–2 mm long. Ovary inferior; carpels 2; syncarpous. Styles 1; 7–8 mm long. Stigmas per ovary 2. Placentation basal. Ovules per ovary 1. Fruit sessile; with calyx persisting; dry; cypselas; elongate-cylindrical; brown; 2–3 mm long; 0.3–0.4 mm wide; glabrous; surface venation ribbed (longitudinally); indehiscent. Seeds 1.
Chromosome information. 2n = 24, or 25, or 48–50.
2n (3x) = 24. Chinnappa and Chmielewski (1987, western North America);
2n (4x) = 36. Krogulevich and Rostovtseva (1984, Siberia);
2n (6x) = 48-50. Afzelius (1924, 1949, 1967, northern Europe); Lövkvist, in Weimarck (1963, Sweden); Zhukova (1964, cultivated plant; 1966, northeastern Asia; 1967b, cultivated plant 2n = 40?); Mosquin and Hayley (1966, northern Canada); Hedberg (1967, northern Canada); Johnson and Packer (1968, northwestern Alaska); Sokolovskaya (1968, northeastern Asia, Koryak, as Senecio arcticus; 1970, northeastern Russia); Zhukova and Tikhonova (1971, 1973, Chukotka); Zhukova and Petrovsky (1972, northeastern Asia; 1976, western Chukotka); Packer and McPherson (1974, Alaska); Löve and Löve (1982a, central Canada); Krogulevich (1976a, northern Siberia); Krogulevich and Rostovtseva (1984, Siberia).
Ploidy levels recorded 3x, 4x, and 6x.
Indigenous knowledge. The young leaves and flowering stems may be eaten as a salad, made into sauerkraut, or cooked as a potherb (Porsild 1953).
Ecology and habitat. Elevation 1–50 m. Substrates: wet meadows, depressions of low-centre polygons, marshes, seashores; imperfectly drained moist areas (a mire plant found in wetlands, and mossy tundra); gravel, sand, silt, clay; with high organic content, peat; calcareous, or halophytic, or nitrophilous, or non-calcareous (plants less than 10 cm high on stony tundra probably low in nitrogen; plants to 30 cm high on an adjacent site where garbage had been burnt, possibly with more nitrogen from the ash, observed on Baffin Island, Nettilling Lake, Nikko Island). Common in wet depressions, near the seashore in salty wet mud (CAN 255629); clay areas with low organic content in patterned Dryas-Cassiope and Carex fuliginosa tundra (CAN 582362).
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. Arctic. Arctic islands: Baffin, Parry islands, Banks, Victoria, Prince of Wales, King William, Southampton, Coats (Prince Charles Island, Boothia, Melville, and Simpson peninsulas).
Northern hemisphere distribution. Circumpolar, or circumboreal. 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, Labrador – Hudson Bay.
General notes. This is the largest annual plant species in the Canadian Arctic Archipelago. "In the early stages of growth, the leaves, stem, and flowering heads are all covered with translucent hairs -- producing a "greenhouse effect" close to the surface of the plant, essentially extending the growing season by a few vital days by allowing the sun to warm the tissues, and preventing the heat from escaping" (Burt 2000, p. 196; see image library).
Porsild and Cody (1980) claim that Tephroseris palustris subsp. congesta (Senecio congestus) is "hapaxanthic" or flowering only once and then dying afterwards. In high latitudes, specimens in which the flowers of the year are killed by early frost may flower and fruit the following year.
Ovenden (1986) found Tephroseris palustris subsp. congesta to be an early colonising species on the lake bed of Illisarvik, the site of a thermokarst lake that was artificially drained in August 1978.
Gloschenko and Martini (1987) studied the vegetation of four river-influenced coastal marshes located between the Moose River and Harricanaw River in southern James Bay. Six major groupings of species were found. These included (1) a salt marsh dominated by Puccinellia phryganodes, P. lucida, Hippuris tetraphylla, and Scirpus maritimus, (2) saline ponds with Tephroseris palustris subsp. congesta, (3) a saline/brackish meadow marsh with Carex paleacea, (4) an intertidal estuarine marsh with Eleocharis palustris, (5) freshwater ponds with Potamogeton filiformis, and (6) a freshwater marsh/fen. Major environmental factors controlling the distribution of these groups include substrate salinity, river flow patterns, storm surges, and tidal range. The marshes described were considered unique in species composition in James Bay and similar to marshes described in the Gulf of Boothia.
Staniforth et al. (1998) noted that coastal ecosystems at high latitudes are exposed to physical disturbances (abrasion by ice, tides, waves, and wind) and to degradation due to the grazing activities of waterfowl. The frequency of disturbance and the regenerative capacity of plants determine the recovery potential for the plant community. They examined the seed bank in soil samples collected from a beach ridge, a drift zone, a sand bar, and a salt marsh at Bird Cove, near Churchill, Manitoba, on the western shoreline of Hudson Bay. Seedling emergence from soil samples after four successive periods of stratification at 5°C totalled 2968 seedlings of 19 species. Mean emerged seedling densities for each ecosystem were (i) 786 seedlings/m2 (beach ridge), (ii) 699 seedlings/m2 (drift zone), (iii) 2875 seedlings/m2 (sand bar), and (iv) 39,204 seedlings/m2 (salt marsh). These densities are much higher than those for temperate coastal ecosystems and for most terrestrial, subarctic ecosystems. Ninety-seven percent of the 2772 identifiable emergents were of three ruderal species: Juncus bufonius, Tephroseris palustris subsp. congesta (S. congestus), and Spergularia marina. These three common species were found from samples collected from all ecosystems except the beach ridge, which had no species in common with the other ecosystems and was dominated by Sagina nodosa and Saxifraga tricuspidata in its seed bank.
Illustrations. • Habitat. Plants growing in a sheltered gully. N.W.T., Banks Island, Sachs Harbour. 27 July, 1981. J.M. Gillett 18861A. CAN. • Close-up of young plant. Plant about 5 cm high developing a capulescence of many capitula that are surrounded by reddish involucral bracts. Note very hairy leaves near the inflorescences and almost glabrous leaves at the base of the plants. Nunavut, Southampton Island, Coral Harbour. Aiken and Brysting 01–078. CAN. • Close-up of young capulescence. Inflorescence composed of 4 flowering heads that are in bud. Each head (capitulum) has numerous disc florets with pinkish undersides of the petals showing. The halo effect is from the dense hairs on the leaves subtending the inflorescence. Nunavut, Southampton Island, Coral Harbour. Aiken and Brysting 01–078. CAN. • Close-up of expanding capulescence. Capulescence composed of numerous capitula, with the central one beginning to open and showing the outer surface of red involucral bracts and the first yellow ray floret petals. Note the long villous hairs on the leaves and capitula. Nunavut, Southampton Island, Coral Harbour. Aiken and Brysting 01–078. CAN. • Side view of capitulescence. Note the long villous hairs on the margins of the leaves and involucral bracts. Nunavut, Southampton Island, Coral Harbour. Aiken and Brysting 01–078. CAN. • Expanding capulescence. Surface view of expanding capulescence with toothed yellow ray petals beside the villous involucral bracts and the subtending leaves. Nunavut, Southampton Island, Coral Harbour. Aiken and Brysting 01–078. CAN. • Flowering capulescence. Surface view of flowering heads that have fully expanded ray florets with strap-like or ray petals, and opening disc florets, some of which show the tips of yellow anthers. Nunavut, Rankin Inlet. Aiken and Brysting 01–055. CAN. • Fly pollination: Close-up of three flies. Flies walking on the flowering heads and in the process, transferring pollen from flower to flower. Nunavut, Rankin Inlet. Aiken and Brysting 01–055. CAN. • Capulescence going to seed. Umbel-like inflorescence of flowering heads in which some have yellow disc and ray florets and others, with a tuft of white pappus hairs on the top, are setting fruit. Nunavut, Rankin Inlet. Aiken and Brysting 01–055. 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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