Flora of the Canadian Arctic Archipelago


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 saxatilis L.

English: Russet sedge,

French: Carex saxatile,

Inuktitut: Iviit, ivisuka, ivitsuskaka; Ivik (Inuvialuktun).

Cyperaceae, Sedge family.

Published in Sp. Pl. : 976. 1753.

Type: Selected by Egorova (1999: 184). Lectotype: LINN 1100.51.

Synonymy. Carex vesicaria L. subsp. saxatilis (L.) Kűkenthal in Engler, Planzenreich 4: 20 (Heft 38): 728. 1909.

Carex pulla Gooden., Trans. Linn. Soc. London 3: 78. pl. 14. 1797.

Carex vesicaria L. subsp. pulla (Gooden.) Andersson, Pl. Scand. 19. Tab 8. 104. 1849.

Carex miliaris Michx., Fl. Bor. Amer. 2: 174. 1803.

Carex saxatilis L. var. miliaris (Michx.) L.H. Bailey, Bot. Gaz. (Crawfordsville) 9: 120. 1884.

Carex physocarpa Presl, Reliq. Haenk. 205. 1828.

Carex vesicaria L. var. physocarpa (Presl) Kűkenthal, in Engler, Pflanzenreich 4:20 (Heft 38): 727. 1909.

Carex compacta R. Br. ex Dewey, Amer. J. Sci. Arts Ser. I, 27: 237. 1835.

Carex ambusta Boott, 3: Illustrations of the genus Carex 64. pl. 172. 1858.

Carex rotundata Wahlenb. var. elatior Lange, Meddel. Grønland 3 (Consp. Fl. Groenl.): 293. 1887.

Carex miliaris Michx., var. obtusa L. Bailey, Mem. Torrey Bot. Club 1: 36. 1889.

Carex miliaris Michx. var. major L. Bailey, Mem. Torrey Bot. Club 1: 36. 1889.

Carex procerula V. Krecz., in Komarov, Fl. URSS, 3:622. 1935.

Carex miliaris Michx., var. ungavensis Raymond, Bull. Soc. Bot. France 99: 196. 1952.

Carex miliaris Michx., f. longepedunculata Lepage, Naturaliste Can. 82: 189. 1955.

Carex saxatilis Michx., f. longepedunculata (Lepage) Lepage, Naturaliste Can. 84: 93. 1957.

Vegetative morphology. Plants (7–)15–30(–90) cm high; perennial herbs; caespitose; loosely tufted in several tufts. Only fibrous roots present. Roots pallid-brown. Ground level or underground stems horizontal; rhizomatous; compact. Ground level or underground stems scales present. Aerial stems erect; not filiform (0.4–1.7(-2.1) mm in diameter above the uppermost leaf). Leaves mainly basal, or distributed along the stems (in the lower third, 3–9 per fertile stem); alternate; marcescent. Petioles absent. Sheaths present; breaking down into fibres; not forming a conspicuous build-up at the base of the plant; brown, or reddish orange (tightly enveloping the stem, hyaline ventrally, mouth truncate or concave); sheath collars present. Ligules present; 0.4–6.6(–10) mm long (as wide as long, to slightly longer than wide, obtuse to the apex). Leaves grass-like. Blades 45–360(–440) mm long, 0.9–4.8(–6.3) mm wide (mid to dark green), somewhat curled, linear, flat or revolute (at the margins), veins parallel. Blade adaxial surface glabrous. Blade margins scabrous (or scaberulous).

Reproductive morphology. Plants monoecious. Flowering stems two or more per plant. Flowering stems triangular in cross section. Flowering stems about as high as the leaves, or conspicuously taller than the leaves; with leaves. Leaf or reduced bract subtending the base of the inflorescence present; conspicuous and leaf-like; similar in length to the inflorescence, or shorter than the apex of the inflorescence (lower leaves on the stem often extend beyond the inflorescence); 6–160(–190) mm long; persistent; sheathless. Inflorescences a spike of spikes; 2.5–14(–20) cm long; 5–45 mm wide. Pedicels scabrous (on ridges). Cladoprophylls present. Inflorescence multispicate. Inflorescence 2–3(–6) spikes (1–3 pistillate spikes erect or proximal spikes often pendent). Individual spike(s) erect. Terminal spike completely staminate. Floral scales shorter than the perigynium in fruit, or as long as the perigynium in fruit; black; with margins and sometimes midvein paler in colour than the adjacent area of the scale; ovate; 1.9–4.3(–5) mm long; 0.9–2.1 mm wide; glabrous; apex acute. Flowers unisexual. Staminate flowers conspicuous. Perianth represented by a perigynium. Stamens present (staminate flowers), or absent (pistillate flowers); 3. Anthers 1.1–3.4(–4.1) mm long. Ovary superior; carpels 3; syncarpous. Perigynia contracted at the base into a stipe (0–0.3(-0.4)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 fused to the apex except for a small aperture through which the style protrudes; broadly ovate; 2.2–4.8(–5.5) mm long; 1.1–3 mm wide; erect or ascending (forming an angle 25–75° with the spike axis); black, or brown; membranous; surface glossy; glabrous; tuberculate (slightly); faintly veined (with few nerves that do not reach to the beak); apices beaked with a short beak (0.2–0.8 mm); apex oblique, becoming slightly bidentate. Fruit sessile; dry; an achene; indehiscent. Achenes lenticular (yellow and smooth); not filling the upper part of the perigynia. Seeds 1.

Chromosome information. 2n = 80.

2n = 80. Heilborn (1928, northern Europe); Löve (1954b?, 1955a?); Löve and Löve (1956, Iceland); Knaben and Engelskjøn (1967, southern Norway); Engelskjøn (1979, northern Norway). Löve and Löve (1975) listed several counts, all as arctic or Scandinavian. Most of these probably belong to subsp. laxa. The ones above probably belong to subsp. saxatilis.

Taxon as an environmental indicator. Carex saxatilis occurs in a wide variety of open moist habitats. It is often found as a dominant in open cyperoid wetlands where it is commonly associated with other species of Carex as well as Eriophorum and Equisetum. Carex saxatilis also occurs in roadside ditches, Sphagnum bogs, sandy beaches, openings in spruce muskeg, seasonally wet ponds, wet gravel, mud flats, and standing water along the shorelines of lakes, ponds, and slow-moving streams. In more southern habitats, C. saxatilis is almost always associated with shoreline habitats and is absent from surrounding graminoid wetlands. This sedge may not compete well with more robust, temperate species and in these southern stations may be reliant on water-level fluctuations to eliminate competing vegetation (Ford and Ball 1992).

Ecology and habitat. Substrates: wet meadows, hummocks, around the margins of ponds, marshes, along streams, river terraces, tundra, seashores (in bogs or on beaches); aquatic, imperfectly drained moist areas, dry; rocks, gravel, sand, silt, clay; with low organic content, with high organic content; calcareous. In drier places, C. saxatilis can be found in grassy meadows. In wetter areas, it is reported with Dryas and mosses. It can occur in higher altitudes where it grows near mountain streams.

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. Common. Arctic. Arctic islands: Baffin, Ellesmere, Axel Heiberg, Banks, Victoria, Southampton, Coats.

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

General notes. In a study of the circumpolar short-beaked taxa of Carex sect. Vesicariae, using numerical analyses of macro-morphological characters, Ford and Ball (1992, p. 620) found that "within the C. saxatilis complex, plants from western North America (C. physocarpa) tend to be robust individuals with long peduncles on the pistillate spikes, wide leaves, and large perigynia. These characters, and others, decrease in size eastward across the North American continent, with intermediate plants usually referred to as C. saxatilis and small plants referred to as C. miliaris." Ford and Ball (1992) concluded that a single distigmatic species, C. saxatilis, should be recognised and present alternative theories for this clinal variation. They noted that anatomically C. saxatilis is indistinguishable from C. membranacea and presented evidence to suggest that "this similarity is the result of homoplasy or stasis in anatomical characters rather than an indication of a close evolutionary relationship." (p. 620).

Elven et al. (2003) considered this an intricate species where perhaps there are three major races or subspecies: "subsp. saxatilis as a mainly boreal-alpine entity in Iceland and mainland Northern Europe, subsp. laxa as an arctic circumpolar entity, and perhaps subsp. miliaris/rhomalea as one or two boreal to Low Arctic entities in northeastern North America and southern Greenland. The southern and northern Greenland plants are very different and must represent different taxa, subspecies or perhaps species. The southern Greenland entity ('miliaris') also extends into the southern arctic parts of northeastern North America, but perhaps not westwards. The northern Greenland plants are identical with the northern North American, Svalbard, and northern Russian plants (e.g., Novaya Zemlya), i.e., subsp. laxa, and different from the mainland European plants, subsp. saxatilis." If this is the case the problem is how to treat the northeastern America and southern Greenland plants. These authors suggest the solution is to keep C. miliaris as a species.

The chromosome counts listed by Löve and Löve (1975) and Löve (1981d) under the name C. miliaris, if reliable, are an additional argument for status as species. (Elven et al. 2003).

Illustrations. • Habitat. Dominant species in this rocky habitat, seen in mid-photo and in foreground. Nunavut, Baffin Island, Iqaluit. Aiken 97–037. CAN. • Habitat. Plants growing between rocks. Nunavut, Baffin Island, Iqaluit. Aiken 97–037. CAN. Scale bar in cm. • Habitat: Cape Dorset. Dominant plant in damp roadside area. Common in hamlet of Cape Dorset. Nunavut, Baffin Island, 2 August, 2005. Aiken. No voucher. • Surface view of spikes. Top view of two inflorescences. In damp area beside road. Nunavut, Baffin Island, Cape Dorset. 2 August, 2005. Aiken. No voucher. • Close-up of inflorescence. A) Terminal staminate spike at anthesis. B) Perigynia with two stigmas. • Close-up of inflorescence. Terminal spike staminate. Middle spike staminate at the apex, pistillate at the base. Lowest spike pistillate. Note the perigynia are brown. • 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.