Carex rupestris All.
Cyperaceae, sedge family.
Fl. Pedem. 2: 264. 1785.
Nomenclatural section used by Flora of North America project subgenus Carex, sect. Petreae (O.F. Lang) Kükenthal
Type: Allioni, Fl. Pedem. 2, tab. 92, 1785. fig. 1, lectotype selected by Egorova (1999?)
Vegetative morphology. Plants perennial herbs; (4–)8–15(–20) cm high; caespitose (loosely); with slender, cord-like horizontal stems and rather stout, scabrous culms, barely longer than the scabrous, flat and somewhat curved leaves. Roots pallid-brown. Ground-level or under-ground stems horizontal; rhizomatous, or stoloniferous (cord-like); elongate. Scales present. Aerial stems erect; not filiform (rather coarse, 0.3–1.2 mm in diameter); triangular in cross-section; scabrous. Leaves in a basal tuft (compact plants), or distributed along the stems (tall plants). Petioles absent. Sheaths persisting; forming a conspicuous build up at the base of the plant, or not forming a conspicuous build up at the base of the plant; brown, or reddish; collars absent. Ligules present (up to 1.5 mm long, apex ovate). Blades 20–150 mm long; 0.5–2.5 mm wide (0.5 mm wide when loosely rolled). Blades somewhat curled; linear; triangular in cross section, or flat, or involute; veins parallel. Blades adaxial surface glabrous, or scabrous (scaberulous seen at 40X). Blade margins scabrous (scaberulous).
Reproductive morphology. Plants monoecious. Flowering stems present. Flowering stems about as high as the leaves; without leaves in the upper half; glabrous. Leaf or reduced bract closely associated with the base of the inflorescence absent. Inflorescence spicate; (0.6–)1–2 cm long; 5–10 mm wide; a single spike. Individual spike(s) erect. Terminal spike staminate at the apex (with a few pistillate flowers at the base). Cladoprophyll present at the base of the peduncle of lateral spikes. Staminate flowers inconspicuous. Floral scales longer than the perigynium in fruit (usually); brown (at the base, hyaline at the apex); with margins, and sometimes midvein paler in colour than the adjacent area of the scale; obtuse; 3–3.5 mm long; 1.5–3 mm wide; glabrous. Perianth absent. Stamens 3. Anthers 1.8–2.2 mm long. Carpels syncarpous. Styles long and thick (extending beyond the beak). Stigmas per style 3. Placentation basal. Fruit surrounded by a perigynium. Perigynia fused to the apex except for a small aperture through which the style protrudes; obovate (oblanceolate); 2.8–3.5 mm long; 2.6–2.9 mm wide; contracted at the base into a stipe-like structure; erect or ascending; golden brown (pale towards the base); membranous; surface dull; glabrous; faintly nerved; apices merely conical or rounded. Fruit an achene. Achenes filling the perigynia; trigonous.
Chromosome information. 2n = 50 and 52. 50 52. - Heilborn (1924 northern Norway, 2n = 50); Flovik (1943 Svalbard?, 2n = 50); Holmen (1952 Greenland, 2n = c.50); Löve and Löve (1956b Iceland, 2n = 50, 1981c northern Canada, 2n = 52); Jørgensen et al. (1958 Greenland, 2n = 52); Favarger (1959a central Europe, 2n = 50); Knaben and Engelskjøn (1967 Norway, 2n = 52); Johnson and Packer (1968 northwestern Alaska , 2n = c. 52); Zhukova and Petrovsky (1971 north eastern Asia, 2n = 50, 1987a northe eastern Asia, 2n = 50); Petrovsky and Zhukova (1978, 2n = 50); Murin (1978 central Europe, 2n = c.50); Druskovic (1995 SE Europe, 2n = 52).
Distribution. Northern hemisphere distribution: circumpolar; Greenland, Canada. Yukon, Northwest Territories Islands, Continental Northwest Territories, Nunavut Islands, Continental Nunavut, Northern Québec. Arctic, or alpine. Range in the Canadian Arctic Archipelago widespread. Common. Arctic Islands: Baffin, Devon, Ellesmere, Axel Heiberg, Banks, Victoria, and Parry Islands (Melville), Somerset, King William, Southampton (and Igloolik).
Ecology and habitat. Substrates: river terraces (older and raised), tundra, slopes, ridges; dry; calcareous; gravel, sand, silt, till (or in various combinations of the above; occasionally also near bedrock outcrops); with low organic content, or peat (older dry deposits). Habitats: This species occurs on dry barrens or tundra where it is found with Dryas, Oxyria, Astragalus, and Poa species. On steeper slopes it is found with Carex nardina and Saxifraga. Geological features associated with this species include till plains, old lake beds with thick peat deposits, sand and gravel morainal systems, drumlin ridges, and gravel kames.
Notes. Polunin (1940) considered this taxon relatively common and
noted that it varies considerably in size according to the local conditions, but
not in any character that is of taxonomic importance.
In a study of
scale-dependent correlation's of Arctic vegetation and snow cover in
south-eastern Victoria Island, Schaefer and Messier (1995) found that C.
rupestris was associated with low snow cover.
Illustrations. • Plants in habitat. The dominant species in a transition zone between tundra and a small marsh. Nunavut, Ellesmere Island, 79°25'N, 75°38'W. Aiken 98–030. Photograph by Mollie MacCormac. • Herbarium specimen. Note long underground stems and somewhat curled leaves CAN 204808. • Close-up of plants. Left hand inflorescence has two mature almost beak-less perigynia. Right hand inflorescence younger and showing anthers at the apex. Nunavut, Ellesmere Island, 79°25'N, 75°38'W. Aiken 98–030, CAN. Photograph by Mollie MacCormac. • Close-up of inflorescence. Unispicate inflorescence with staminate flowers at the apex and pistillate flowers at the base. CAN 484975. • Arctic Island distribution.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
