Flora of the Canadian Arctic Archipelago

DELTA Home

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

Carex ursina Dewey

Cyperaceae, Sedge family.

Published in Amer. J. Sci. Arts. 27: 240. 1835.

Type: Described from arctic America. Holotype: GH.

Vegetative morphology. Plants 2–6(–10) cm high (CAN 18360); perennial herbs; caespitose (densely). Only fibrous roots present. Roots pallid-brown. Ground level or underground stems horizontal (short); rhizomatous; compact. Ground level or underground stems scales present. Aerial stems erect; not filiform (0.3–1.0 mm in diameter). Leaves mainly basal; alternate; marcescent. Petioles absent. Sheaths present; persisting; not forming a conspicuous build-up at the base of the plant; greyish brown; sheath collars absent. Ligules present. Leaves grass-like. Blades 10–50 mm long, 0.5–0.8 mm wide, straight, linear, folded, veins parallel. Blade adaxial surface glabrous (midvein scaberulous towards the leaf apex). Blade margins scabrous (scaberulous).

Reproductive morphology. Plants monoecious. Flowering stems two or more per plant. Flowering stems triangular in cross section. Flowering stems shorter than the leaves, or about as high as the leaves; without leaves. Leaf or reduced bract subtending the base of the inflorescence absent. Inflorescences head-like (usually a single spike, rarely with a second spike); globose or sub-globose; 0.4–0.8 cm long; 4–6 mm wide. Cladoprophylls absent. Inflorescence unispicate. Inflorescence with 7–15 perigynia. Individual spike(s) erect. Terminal spike staminate at the base. Floral scales shorter than the perigynium in fruit; brown; with margins the same colour as the body of the scale; ovate (broadly); 2.2–2.6 mm long; 1.6–2 mm wide; glabrous; apex obtuse. Flowers unisexual. Staminate flowers inconspicuous. Perianth represented by a perigynium. Stamens present (staminate flowers), or absent (pistillate flowers); 3. Anthers 1–1.3 mm long. Ovary superior; carpels 3; syncarpous. Perigynia contracted at the base into a stipe (approximately 0.5 mm long). Styles 2; partially fused; slender, extending beyond the beak. Stigmas per ovary 2. Placentation basal. Ovules per ovary 1. Fruit surrounded by a perigynium. Perigynia with a slit running down the beak on the abaxial side through which the style protrudes; globose, or sub-globose, or broadly ovate; (1.8–)2.3–2.7 mm long; 2.1–2.3 mm wide; spreading at maturity; straw-coloured, or whitish (greyish green); membranous; surface dull; glabrous; papillose; faintly veined; with 2 keels; apices merely conical or rounded. Fruit sessile; dry; an achene; indehiscent. Achenes lenticular; filling the perigynia. Seeds 1; about 1.2 mm long × 0.7–1.1 mm wide; brown (reddish, dull to slightly glossy).

Chromosome information. 2n = 64.

2n = 64. Flovik (1943, Svalbard); Jørgensen et al. (1958, Greenland); Zhukova and Petrovsky (1971, Wrangel Island); Zhukova and Tikhonova (1971, Chukotka); Zhukova et al. (1973, northeastern Asia); Packer and McPherson (1974, northern Alaska); Löve (1981d, northern Canada); Petrovsky and Zhukova (1983, northeastern Asia).

Ecology and habitat. Substrates: wet meadows, around the margins of ponds (brackish; also in peat bogs), marshes (salt), tundra, seashores (tidal flats, beach ridges and in silt near the mouths of rivers); imperfectly drained moist areas; gravel, sand, silt, clay; with low organic content, with high organic content; halophytic. A pronounced littoral species of sheltered sea and lagoon shores, subject to flooding by high tide. It is often a dominant species, forming dense mats, and can be found with Puccinellia phryganodes and Stellaria humifusa.

North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec. Range in the Canadian Arctic Archipelago widespread. Common. Coastal. Arctic islands: Baffin, Devon, Ellesmere, and Axel Heiberg (new since Porsild 1957), Parry islands (Melville and Prince Patrick, both new since Porsild 1957), Banks, Victoria, Somerset, King William, Southampton, and Coats (Prince Charles and Vansittart Islands).

Northern hemisphere distribution. Circumpolar. Svalbard – Franz Joseph Land, Polar Ural – Novaya Zemlya, Yamal–Gydan, Taimyr – Severnaya Zemlya, Anabar–Olenyok, Kharaulakh, Yana–Kolyma, West Chukotka, Wrangel Island, East Chukotka, West Alaska, North Alaska – Yukon, Central Canada, Labrador – Hudson Bay, Ellesmere Land – Peary Land, West Greenland, East Greenland.

General notes. Polunin (1940, p. 113) noted that "except in the Far North, where it is rather rare, the species is probably common along the seashores wherever these are muddy or of damp sand, its dense tussocks being locally very abundant, or coalescing to form extensive mats around the high-water mark in sheltered lagoons...After Puccinellia phryganodes it is about the most important salt marsh plant within our area [in the eastern Arctic], forming a characteristic association with this species and Stellaria humifusa." Such an association is found at Sylvia Grinnell Park, Iqaluit, and illustrated in the image library.

Illustrations. • Habitat - roadside. Zone of plants growing beside a road. Eriophorum plants in background. Scale bar in cm. Nunavut, Baffin Island, Iqaluit, near airport. August, 1997. Aiken and McJannet 97–039. CAN. • Habitat. Several yellow-green plants scattered throughout saline meadow. One large plant being photographed. Nunavut, Baffin Island, Iqaluit. Aiken 97–038. CAN. • Habitat. Close-up of tufted plant from previous image. Bright green plants are Honckenya peploides, a characteristic associate. Nunavut, Baffin Island, Iqaluit. Aiken 97–038. CAN. Scale bar in cm. • Close-up of plant. Closeup of tufted plant from previous photo, near plants of Puccinellia phryganodes and Honckenya peploides. Nunavut, Baffin Island, Iqaluit. Aiken 97–038. CAN. Scale bar in cm. • Rhizomatous base of plant. Note rhizomatous base of plant lacking marcescent leaves. Inflorescences unispicate. Nunavut, Foxe Basin, Prince Charles Island. 15–18 August, 1949. Baldwin 1903. CAN 203385. • Close-up of inflorescences. Unispicate subglobose inflorescences shorter than or as tall as the leaves. Nunavut, Baffin Island, Iqaluit. Aiken 97–038. CAN. • Close-up of inflorescence. Inflorescence unispicate and subglobose. Floral scales uniform in colour and much shorter than the almost beakless perigynia. Remains of staminate flowers can be seen at the base on the left-hand side. • Germinating seedling. Seedlings with the perigynia remaining. New plant growth from achene, near its point of attachment with perigynium. Drawing by S. Bergh and L. Barstad based on Svalvard, Dickson Land, Dicksondalen, beneath Mt. Rebbingen, J. Lid. 24 August, 1924. O. With permission of the Botanical Museum, University of Oslo, Norway. • 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.

.

Contents