Flora of the Canadian Arctic Archipelago
English: Sheathed sedge,
French: Carex engaîné,
Inuktitut: Iviit, ivisuka, ivitsuskaka.
Cyperaceae, Sedge family.
Published in Flora 4: 577. 1821.
Type: Described from central Europe: the Sudeten Mountains. Holotype: PRC.
Synonymy. Carex quasivaginata C.B. Clarke, Bull. Misc. Inform. Add., ser. 8, 79. 1908.
?Carex panicea L. var. (beta) sparsiflora Wahlenb., Fl. Lapp. 236. 1812.
?Carex sparsiflora (Wahlenb.) Steud., Nomencl. Bot., ed. 2, 1: 296. 1841.
?Carex algida Turcz. ex V.Krecz., in Kom., Fl. USSR 3: 345, 612. 1935.
Carex vaginata subsp. quasivaginata (C.B. Clarke) Malyschev, Vysok. Fl. Vost. Sajana 90. 1965.
Vegetative morphology. Plants (7–)10–20(–40) cm high (-70 cm high on continental North America); perennial herbs; not caespitose (forming loose clusters). Only fibrous roots present. Ground level or underground stems horizontal; rhizomatous, or stoloniferous; elongate, or compact. Ground level or underground stems scales present. Aerial stems erect; not filiform (0.6–1.3 mm in diameter). Leaves present; distributed along the stems (proximal sheaths bladeless); alternate; marcescent. Petioles absent. Sheaths present; breaking down into fibres (pale brown, slender 0.7–2.8 mm in diameter, not or only very sparsely papillose); not forming a conspicuous build-up at the base of the plant; greyish brown (pallid); sheath collars absent. Ligules present; 2–4.5 mm long (longer than wide). Leaves grass-like. Blades 30–150 mm long (-400 mm long further south; those of the fertile culms less than 100 cm), 1–3.6(–4) mm wide, straight, linear, flat, veins parallel. Blade adaxial surface glabrous or scabrous (minutely scaberulous on leaf margins). Blade margins scabrous (scaberulous).
Reproductive morphology. Plants monoecious. Flowering stems circular or oval in cross section. Flowering stems conspicuously taller than the leaves; with leaves, or without leaves. Leaf or reduced bract subtending the base of the inflorescence present; conspicuous and leaf-like, or reduced, or scale-like; shorter than the apex of the inflorescence (usually); 4–10(–30) mm long (sheath 10–35 mm long; blade10–15 mm long); persistent (inflated); with sheath longer than the blade (or bladeless). Inflorescences a raceme of spikes; (3–)5–10(–20) cm long; 2–7(–15) mm wide. Cladoprophylls present. Inflorescence multispicate. Inflorescence 2–3(–4) spikes (lateral spike suberect with 3–10 flowers, 4–10 mm long × 2–2.5 mm wide). Individual spike(s) ascending (lax, the staminate one on a somewhat stout divergent pedicel). Terminal spike completely staminate (pistillate spikes linear, 8–30 mm long × 3–6.5 mm wide, with 3–15 perigynia, the proximal loosely arranged). Floral scales shorter than the perigynium in fruit; orange-brown (purple tinged); with margins and sometimes midvein paler in colour than the adjacent area of the scale (midvein broad and green); ovate, or lanceolate; 1.8–2.8 mm long; 1.4–1.8 mm wide; glabrous; apex acute (broadly). Flowers unisexual. Staminate flowers conspicuous (pistillate spikes linear). Perianth represented by a perigynium. Stamens present (staminate flowers), or absent (pistillate flowers); 3. Anthers 3–3.5 mm long. Ovary superior; carpels 3; syncarpous. Perigynia sessile. Styles 3; partially fused; slender, not extending beyond the beak. Stigmas per ovary 3. 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; lanceolate, or broadly ovate; 2.2–3(–5) mm long; 1.2–1.5(–2.2) mm wide; erect or ascending; straw-coloured, or brown, or green; membranous; surface dull; glabrous; faintly veined; not keeled; apices beaked with a long beak (cylindrical (0.4-)0.6–1.8(-2.2) mm long); apex oblique, becoming slightly bidentate. Fruit sessile; dry; an achene; indehiscent. Achenes trigonous (light to dark brown); not filling the upper part of the perigynia. Seeds 1.
Chromosome information. 2n = 30 and 32.
2n = 30 and 32. For the collective species. Heilborn (1922, northern Europe; 1924, southern Norway, 2n = 30, 32, as 'sparsiflora', 1932)
2n = 32, as 'sparsiflora'; Löve and Löve (1956, Iceland; 1965); Löve (1981d, central Canada);
2n = 32. Knaben (1950, southern Norway, as 'vaginata'); Löve and Ritchie (1966, northern Canada, as 'vaginata'); Zhukova and Tikhonova (1971, Chukotka, as 'algida'); Dietrich in Löve (1972, as 'sparsiflora'); Krogulevich (1976a, northern Siberia, as 'vaginata'); Zhukova et al. (1977, northeastern Asia, as 'vaginata'); Yurtsev and Zhukova (1978, eastern Chukotka, as 'algida'); Zhukova and Petrovsky (1980, western Chukotka, as 'vaginata').
Ecology and habitat. Substrates: depressions of low-centre polygons, tundra, slopes (and ledges); imperfectly drained moist areas; silt, till; calcareous. Found infrequently on rolling or gently sloping till plains on turf or with Dryas. On slopes, it has been reported with Salix richardsonii and ericaceous shrubs. Polunin (1940) noted that it occurs in marshy lowland areas that are not too wet in summer or too overgrown by ranker species and that it also occurs on better drained, grassy areas and among heaths where the surface is dry, although just underneath there is generally a plentiful supply of water.
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. Uncommon. Low Arctic. Arctic islands: Baffin (Kimmirut), Banks (Bernard River, a new record since Porsild 1957), Victoria and Southampton (Coral Harbour).
Northern hemisphere distribution. Circumpolar, or circumboreal. Northern Iceland, Northern Fennoscandian, KaninPechora, Polar Ural Novaya Zemlya, YamalGydan, Taimyr Severnaya Zemlya, AnabarOlenyok, Kharaulakh, YanaKolyma, West Chukotka, Wrangel Island, South Chukotka, East Chukotka, West Alaska, North Alaska Yukon, Central Canada, Labrador Hudson Bay, East Greenland.
General notes. Rothrock and Reznicek (2002, p. 428), in the Flora of North America treatment, noted that "Fernald (1950) pointed out that North American plants sometimes segregated as Carex saltuensis do not appear to be sufficiently distinct to warrant recognition as a separate species. T.V. Egorova (1999) recognised both C. saltuensis and C. vaginata, the latter with two subspecies, in North America. More research is clearly needed on this complex circumpolar entity. The inclusion of C. vaginata in sect. Paniceae is uncertain. Unlike other members of the group, C. vaginata lacks papillae on abaxial leaf epidermis, peduncle, and perigynium."
Elven et al. (2003) recognise all the arctic plants, including those from the Canadian Arctic Archipelago, as subsp. quasivaginata and as clearly different from C. vaginata Tausch. s.s. as typified. There are, however, doubts about the name. The name 'sparsiflora' might be the correct one, but this name has not yet been recombined as a subspecies.
In a study correlating Arctic vegetation and snow cover in southeastern Victoria Island, Schaefer and Messier (1995) found that C. vaginata exhibited positive associations with various measures of snow cover. It is thought that snow cover may reduce the rate of desiccation, protect plants from abrasion, and insulate from low temperatures.
Illustrations. • Herbarium specimen. Plants with conspicuously long horizontal stems. CAN 259371. • Herbarium specimen. Right, stems with terminal staminate inflorescences at anthesis; lower pistillate spikes are younger and not yet conspicuous. CAN 151928. • Herbarium specimen. Plant with inflorescence spikes that are widely spaced. Terminal spike staminate, lateral spikes pistillate. Note the long horizontal stems. CAN 26964. • Close-up of inflorescence. Terminal spike staminate. Lateral spikes pistillate and widely spaced in the inflorescence with the base surrounded by the subtending leaf. Floral scales shorter than the perigynia with margins and midveins pale. Perigynia with long beaks. CAN 279152. • 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..