Carex ursina Dewey
Amer. J. Sci. Arts. 27: 240. 1835.
Nomenclatural section used by Flora of North America project subgenus Vignea, sect. Glareosae G. Don
Plants caespitose. Plants less than 15 cm high; 2–6(–10) cm high. Roots pallid-brown. Ground level or underground stems horizontal, or not developed horizontally or vertically; compact. Scales present. Aerial stems erect; not filiform (0.3–1.0 mm in diameter); triangular in cross section; glabrous. Leaves mostly basal. Sheaths greyish brown. Ligules present. Blades straight; linear; folded; glabrous (margins and mid-vein scaberulous towards the leaf apex).
Flowering stems shorter than the leaves, or about as high as the leaves. Leaf or reduced bract closely associated with the base of the inflorescence absent. Inflorescence spicate, or head-like; globose or subglobose; 0.4–0.8 cm long; 4–6 mm wide; a single spike, or multispicate (rarely). Individual spike(s) erect. Terminal spike staminate at the base. Cladoprophyll absent. Staminate flowers inconspicuous. Floral scales shorter than the perigynium in fruit; brown; with margins the same colour as the body of the scale; obtuse; 2.2–2.6 mm long; 1.6–2 mm wide; glabrous. Perianth absent. Anthers 1–1.3 mm long. Styles slender, extending beyond the beak. Stigmas per style 2. Fruit surrounded by a perigynium. Perigynia with a slit running down the beak on the abaxial side through which the style protrudes; globose, or subglobose, or broadly ovate; (1.8–)2.3–2.7 mm long; 2.1–2.3 mm wide; contracted at the base into a stipe-like structure (approximately 0.5 mm long); spreading at maturity; straw-coloured, or whitish (greyish green); surface dull; glabrous; papillose; faintly nerved; with 2 keels; apices merely conical or rounded. Achenes filling the perigynia; lenticular.
Chromosome information. 2n = 64.
Distribution. Circumpolar. Coastal. Range in the Canadian Arctic Archipelago wide-spread. Common. 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, King William, Southampton, and Coats (as well as Prince Charles, and Winter Islands).
Ecology and habitat. Substrate wet meadows, around the margins of ponds (brackish; also in peat bogs), marshes (salt), tundra, sea shore (tidal flats, beach ridges and in silt near the mouths of rivers); imperfectly drained; halophytic; gravel, sand, silt, clay; with low organic content, or with high organic content. 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.
Notes. Polunin (1940) noted that except in the Far North, where this species is rather rare, it is probably common along the seashore wherever there are muddy or of damp sand. Its dense tussocks can be locally very abundant, or coalesce to form extensive mats around high-water mark in sheltered lagoons. Polunin (1940) considered that after Puccinellia phryganodes this is the most important salt marsh plant in the eastern Arctic, forming a characteristic association with this species and Stellaria humifusa. Such as association is found at Sylvia Grinell Park, Iqaluit and illustrated in the image library.
Illustrations. • Plants in habitat. Meadow just above high tide line. Nunavut, Baffin Island, Iqaluit. Susan Aiken 97–038, CAN. • Plants in habitat. Close-up of tufted plant from previous image. Light green plants are Stellaria humifusa, a charateristic associate. Nunavut, Baffin Island, Iqaluit. Susan Aiken 97–038, CAN. Scale bar in cm. • Close-up of plant. Close-up of plant growing in a clump with Puccinellia phryganodes. Nunavut, Baffin Island, Iqaluit. Susan Aiken 97–038, CAN. Scale bar in cm. • Close-up of inflorescences. Unispicate subglobose inforescences. Nunavut, Baffin Island, Iqaluit. Susan Aiken 97–038, CAN. • Close-up of Inflorescence. Floral scales uniform in color and much shorter than the perigynia which are almost beakless. • Germinating seedling. Seedling with perigynia left, and new plant growth from near the point of attachment of the peryigynia. Drawing by S. Bergh and L. Barstad based on Svalvard: Dickson Land, Dicksondalen beneath Mt. Rebbingen, J. Lid, 24 Aug. 1924. O. With permission of the Botanical Museum Univeristy of Oslo, Norway. • Arctic Island distribution.
Cite this publication as: Aiken, S.G., Boles, R.L., and Dallwitz, M.J. 1999 onwards. ‘Cyperaceae of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval.’ Version: 6th November 2000. http://http://www.mun.ca/biology/delta/arcticf/. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
