Flora of the Canadian Arctic Archipelago
| Flora of the Canadian Arctic Archipelago | |
English: Bigelow's sedge,
French: Carex de Bigelow,
Inuktitut: Iviit, ivisuka, ivitsuskaka.
Cyperaceae, Sedge family.
Published in Ann. Lyceum Nat. Hist. New York 1: 67. 1824.
Type: Described from USA: New Hampshire, White Hills. Holotype: PH.
Synonymy. Carex anguillata Drejer, Fl. Dan..t. 2846; Revis. Caric. 36. 1838. (?)
Carex hyperborea Drejer, Naturhist. Tidsskr. 3: 43. 1841.
Carex concolor auct. non R.Br.
Carex vulgaris auct, non Fr.
Vegetative morphology. Plants 3–20(–30) cm high; perennial herbs; not caespitose. Only fibrous roots present. Roots pallid-brown. Ground level or underground stems horizontal; rhizomatous, or stoloniferous; elongate. Ground level or underground stems scales present. Aerial stems erect. Leaves present; mainly basal; alternate; marcescent. Petioles absent. Sheaths present; persisting (first year), or breaking down into fibres (with age); not forming a conspicuous build-up at the base of the plant; greyish brown, or brown; sheath collars absent. Ligules present. Leaves grass-like. Blades (40–)80–160(–200) mm long, 0.5–2.5(–3.5) mm wide, straight, linear, flat or revolute, veins parallel, not septate nodulose (distinguishes this species from C. aquatilis). Blade adaxial surface glabrous (strongly ribbed). Blade abaxial surface glabrous. Blade margins scabrous (scaberulous at the tip); apices acuminate.
Reproductive morphology. Plants monoecious. Flowering stems two or more per plant. Flowering stems triangular in cross section. Flowering stems 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; 25–35 mm long; persistent; sheathless (the base of the blade may enclose the stem at the node, but there is no sheath covering any part of the internode). Inflorescences a spike of spikes (on stiff erect very short pedicels); (1.5–)3–6(–8) cm long; (5–)10–15 mm wide. Pedicels glabrous. Cladoprophylls present. Inflorescence multispicate. Inflorescence 2–3(–4) spikes. Individual spike(s) erect (lateral spike pistillate, 2–30 mm long × -4 mm wide). Terminal spike completely staminate (usually, the proximal pistillate spike loosely flowered, base often attenuate, less often cuneate, a contrast with subsp. lugens). Floral scales shorter than the perigynium in fruit (green sides of the perigynia visible around the edges of the darker scales); black; with margins darker in colour than the midvein (midvein light brown or green); ovate (broadly, or oblong); 2.5–3.5 mm long; 1.2–2 mm wide; glabrous; apex obtuse. Flowers unisexual. Staminate flowers conspicuous. Perianth represented by a perigynium. Stamens present (staminate flowers), or absent (pistillate flowers); 3. Anthers 3.3–3.7 mm long. Ovary superior; carpels 3; syncarpous. Perigynia contracted at the base into a stipe. Stipes 0.15–0.45 mm long. Styles 2; partially fused; slender, not 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; 2.3–3 mm long; 1.3–1.7 mm wide; erect or ascending; green (often with purple-black spots at the apex, not uniformly coloured, apex acute, sometimes rounded); membranous; surface dull; glabrous; papillose (minutely); appearing veinless; with 2 keels; apices merely conical or rounded. Fruit sessile (virtually so); dry; an achene; indehiscent. Achenes lenticular; filling the perigynia. Seeds 1.
Chromosome information. 2n = 68 and 70 (Faulkner 1972).
2n = 70. Löve and Löve (1966b, northeastern USA); Löve (1981d, northern Canada).
Ecology and habitat. Substrates: hummocks (mossy), along streams, tundra (often windswept), slopes, ridges (also raised sandy beaches), cliffs; dry, imperfectly drained moist areas (less commonly); rocks, gravel, sand; with low organic content. Typically found in high, dry ledges and ridges; also in sandy areas between boulders. Common associates in this habitat are Empetrum and Arctous. Carex bigelowii also occurs in meadows with other Carex and with Eriophorum. It is somewhat less commonly found in moist tundra and along streams.
North American distribution. 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, Devon, Ellesmere, Southampton, and Banks (literature record; most probably a misidentification of subsp. lugens; also Digges and Resolution Islands).
Northern hemisphere distribution. North American (American Atlantic). Central Canada, Labrador – Hudson Bay, Ellesmere Land – Peary Land, West Greenland, East Greenland.
General notes. This taxon is widespread and variable in the eastern Arctic, varying from strongly stoloniferous and 10–40 cm high to closely tufted and only 4–5 cm high (Polunin 1940). A form with narrow perigynia and long and stiff peduncles to the lower spikes, is sometimes separated as C. anguillata. Polunin (1940) concluded it was best to include this and all other forms in the eastern Arctic under the same name, and this has generally been done.
McLaren (1964) indicated that C. anguillata was an addition to the flora of the Arctic Archipelago. He collected two specimens on Baffin Island at Ogac Lake (specimens at CAN). They are relatively delicate plants but within the concept of C. bigelowii. Another specimen, CAN 204794, collected from the head of Clyde Inlet, Baffin Island, was annotated by Porsild (1958) as ?C. anguillata (Drejer) Fern; "a peculiar form in which the terminal spikes are female at most with 1–2 male flowers near the summit". These document the considerable variation that is known in C. bigelowii. Polunin (1940) discussed why the names C. concolor R. Br. and C. rigida Good. cannot be used. Porsild and Cody (1980) noted that in moist areas the plants become taller and occasionally have longer and more lax-flowered pistillate spikes.
Chater (1980) noted that this is an extremely variable species whose infraspecific taxonomy is confused by its apparent similarity to small variants of Carex aquatilis in the arctic, by the occurrence of numerous hybrids, and by the fact that published work on it has never taken full account of the variation over the entire range.
Carex bigelowii is self-compatible, but protandry limits pollination within flowering shoots (Jonsson et al. 1996). Their study of genetic diversity using allozyme electrophoresis revealed extensive genetic diversity, and indicated high levels of outbreeding in the past. Today, the species produces many seeds and has a large, long-lived seed bank; yet very little seedling recruitment has been observed. In Iceland, seedling recruitment has been observed only in disturbed sites. Reproduction is mainly by vegetative clonal growth (also observed in Swedish Lapland by Wikberg et al. 1994). The long internodes of the rhizomes break down over time, resulting in a large number of independent fragments with the same genetic composition (Jonsson et al. 1996).
The impact of the anticipated climate changes on the population growth and vegetative spread of Carex bigelowii was investigated by Carlsson and Callaghan (1994). They showed that increases in nutrients, carbon dioxide, and temperature (expected consequences of climate change in the Arctic) will lead to increased growth of the species, and that young "guerrilla" type tillers will contribute significantly to vegetative spread.
Demographic aspects in populations of the species were studied in Swedish Lapland by Wikberg et al. (1994) at three altitudes. Tiller densities from the highest altitudes increased significantly during the study period (10–20 years), while those from intermediate and lower altitudes stayed constant.
Experimental control of flowering was investigated by Heide (1992).
Illustrations. • Habitat, meadow: Baffin, Ogac. Grass-like plants near the marker and the dominant plant in the meadow at the base of a dry tundra hillside. Nunavut, Baffin Island, Ogac Lake. 14 July, 2005. Aiken and LeBlanc 04–089a. CAN 586560. • Lemming nest in meadow: Baffin, Ogac. Lemming nest near the marker apparently made from Carex bigelowii leaves in the adjacent meadow (previous image). Aiken and LeBlanc 04–089a. CAN 586560. • Habitat: Iqaluit. Rhizomatous and loosely tufted plants with yellow staminate heads above and black pistillate spikes below, growing between the markers. Plants forming low mats in high, dry sand beside a road. Nunavut, Baffin Island, Iqaluit. 5 July, 2004. Aiken and LeBlanc 04–006. CAN 586478. • Close-up of plants: Dorset. Plants growing in mossy tundra. Nunavut, Baffin Island, Cape Dorset. 4 August, 2005. Aiken. No voucher. • Inflorescence with young stigmas. Young multispicate inflorescences with anthers developing in the terminal totally staminate spike. Pistillate spikes below with two white stigmas exposed. Nunavut, Baffin Island, Iqaluit. 5 July, 2004. Aiken and LeBlanc 04–006. CAN 586478. • Close-up of young inflorescence. Emerging inflorescence with staminate terminal spike beginning to show anthers and two lower pistillate spikes with white stigmas becoming exposed. Nunavut, Baffin Island, Iqaluit. 5 July, 2004. Aiken and LeBlanc 04–006. CAN 586478. • Close-up of inflorescence. Note leaf subtending the inflorescence is shorter than the inflorescence, two pistillate spikes with two white stigmas per perigynium and a terminal all staminate spike. Nunavut, Baffin Island, Ogac Lake. 13 July, 2004. Aiken and LeBlanc. CAN. • Close-up of inflorescence. Flowering stem with subtending leaf that is shorter than the inflorescence, terminal spike male with brown post-anthesis anthers, and lower spike female with post-receptive stigmas. Aiken and Iles 02–042. CAN. • 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.
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