Carex rupestris All.
Fl. Pedem. 2: 264. 1785.
Nomenclatural section used by Flora of North America project subgenus Carex, sect. Petreae (O.F. Lang) Kükenthal
Carex rupestris All. var. rupestris
Carex rupestris var. drummondiana (Dewey) Bailey
Carex rupestris subsp. drummondiana (Dewey) Holub
Plants not caespitose. Plants with unbranched stems in loose clusters; less than 15 cm high (usually); (4–)8–15(–20) cm high. Roots pallid-brown. Ground level or underground 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 mostly basal (compact plants), or distributed along the stems (tall plants). Sheaths brown, or reddish. Ligules present (up to 1.5 mm long, apex ovate). Blades somewhat curled; linear; triangular in cross section, or flat, or involute; glabrous, or scabrous (scaberulous seen at 40X).
Flowering stems about as high as the leaves. 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 mid-vein paler in colour than the adjacent area of the scale; obtuse; 3–3.5 mm long; 1.5–3 mm wide; glabrous. Perianth absent. Anthers 1.8–2.2 mm long. Styles long and thick (extending beyond the beak). Stigmas per style 3. 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); surface dull; glabrous; faintly nerved; apices merely conical or rounded. Achenes filling the perigynia; trigonous.
Chromosome information. 2n = 50 and 52.
Distribution. Circumpolar. Arctic, or alpine. Range in the Canadian Arctic Archipelago wide-spread. Common. Arctic Islands: Baffin, Devon, Ellesmere, Banks, Victoria, and Parry Islands (Melville), Axel Heiberg, Somerset, and Southampton.
Ecology and habitat. Substrate 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). This species occurs on dry barrens or tundra where it is found with Dryas, Oxyria, Astragalus, and Poa alpigena. 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 southeastern 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 t;undra and a small marsh. Nunavut, Ellesmere Island, 79°25'N, 75°38'W. S.G. 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. S.G. 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: 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).
