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 krausei Boeck.

English: Krause's sedge,

French: Carex de Krause,

Inuktitut: Iviit, ivisuka, ivitsuskaka.

Cyperaceae, Sedge family.

Published in Bot. Jahrb. Syst. 7: 279. 1886.

Type: Alaska: Gebiet des Lynn-Canals, Sandinsel in Chilicot unterhalb Katkwälta, 17.06.1882, leg. A. and A. Krause 92, selected by Egorova (1999). Holotype in B lost; an isotype was selected as lectotype. Lectotype: LE.

Synonymy. Carex capillaris L. var. nana (Cham. ex Steud.) f. krausei (Boeck.) Kükenthal in Engl., Pflanzenreich 38, IV, 20: 591. 1909.

Carex capillaris L. subsp. krausei (Boeck.) Böcher, Meddel. Grønland 147, 9: 52. 1952.

Carex capillaris L. var. porsildiana Polunin, J. Linn. Soc. Bot. 52: 373. 1943.

Carex krausei Boeck. subsp. porsildiana (Polunin) ?. Löve and D. Löve, Acta Hort. Gothob. 20: 175. 1956.

Carex capillaris L. subsp. robustior (Drejer ex Lange) Böcher, Meddel. Grønland 147, 9: 51–52. 1952.

Carex boecheriana Á. Löve, D. Löve and Raymond, Can. J. Bot. 35: 748. 1957.

Vegetative morphology. Plants 5–15(–20) cm high (-35 cm high on continental North America); perennial herbs; caespitose. Only fibrous roots present. Roots pallid-brown. Ground level or underground stems absent. Aerial stems erect, or ascending; filiform. Leaves mainly basal; alternate; marcescent. Petioles absent. Sheaths present; persisting; forming a conspicuous build-up at the base of the plant (sometimes); brown, or straw-coloured pale yellow (grey); sheath collars absent. Ligules present; 0.5–1 mm long; membranous. Leaves grass-like. Blades 25–65 mm long, 1–2 mm wide, linear, flat or folded or channelled, veins parallel. Blade adaxial surface glabrous. Blade abaxial surface scabrous (scaberulous). Blade margins scabrous; apices acuminate.

Reproductive morphology. Plants monoecious. Flowering stems triangular in cross section (slightly). 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 (usually, somewhat remote); shorter than the apex of the inflorescence; 5–30 mm long; sheathless. Inflorescences a raceme of spikes; 2–6.5 cm long; 10–20 mm wide. Pedicels glabrous. Cladoprophylls present. Inflorescence multispicate. Inflorescence 3–5 spikes ((-10) proximal spikes 6–10 mm long × 2–3 mm wide, each with 10–12 flowers, usually drooping). Individual spike(s) ascending, or divergent (usually), or pendent. Terminal spike staminate at the base (the staminate portion, level with, or overtopped by, some lateral spikes, the terminal spike 7–10 mm long and 1.3–1.5 mm wide; staminate scales brown with paler margins, oblong-ovate 2–2.8 mm long × 1–2 mm wide). Floral scales shorter than the perigynium in fruit; with margins and sometimes midvein paler in colour than the adjacent area of the scale (midvein conspicuously pale, cf. C. capillaris); ovate, or obovate; 1.5–2 mm long; 1–1.4 mm wide; glabrous; apex rounded, or obtuse (mucronate). Flowers unisexual. Staminate flowers inconspicuous (at the base of the terminal spike). Perianth represented by a perigynium. Sepals modified (but not a pappus). Stamens present (staminate flowers), or absent (pistillate flowers); 3. Anthers 1.3–1.5 mm long. Ovary superior; carpels 3; syncarpous. Perigynia contracted at the base into a stipe (0.2–0.4 mm long, conspicuous when compared with almost sessile C. capillaris perigynia). Styles 3; 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; 1.8–2.1 mm long; 0.8–1 mm wide; spreading at maturity; straw-coloured, or golden brown, or green (conspicuously pale); membranous; surface glossy; glabrous; faintly veined, or appearing veinless (except for two marginal veins); not keeled; apices beaked with a short beak (0.3–0.7 mm long); apex not bidentate or oblique, or oblique, becoming slightly bidentate. Fruit sessile; dry; an achene; obovate; indehiscent. Achenes trigonous; filling the perigynia. Seeds 1.

Chromosome information. 2n = 36, 52, 62.

2n = 36. Löve and Löve (1956, Iceland, probably refers to 'porsildiana'); Löve et al. (1957, Alaska, Juneau, refers to 'krausei' s.s.); Löve (1981d, central Canada).

2n = 56. Löve et al. (1957, 'boecheriana'); Löve (1981d, northern Canada, 'boecheriana').

2n = 62. Yurtsev and Zhukova (1978, eastern Chukotka; 1982, northern Siberia, 'krausei' s.s.).

Ecology and habitat. Substrates: wet meadows, along streams, tundra, barrens (alluvial fans and fens), seashores (wet clay above high tide line, northeastern Canada (CAN 342902)); imperfectly drained moist areas; sand, silt, clay; calcareous. Well-drained sandy silt. Sparsely vegetated marine reworked calcareous sand and silt. Sparse in Dryas barrens (CAN 489228).

North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut. Range in the Canadian Arctic Archipelago limited. Uncommon. Arctic. Arctic islands: Baffin, Ellesmere, Victoria, Coats.

Northern hemisphere distribution. Circumpolar (with large gaps). Northern Iceland, Svalbard – Franz Joseph Land, Polar Ural – Novaya Zemlya, Taimyr – Severnaya Zemlya, Anabar–Olenyok, Kharaulakh, West Chukotka, East Chukotka, West Alaska, North Alaska – Yukon, Central Canada, Labrador – Hudson Bay, Ellesmere Land – Peary Land, West Greenland, East Greenland.

General notes. Polunin (1940) noted that most plants of this species in the eastern arctic varied between 5 and 15 cm in height and recognised those that are much smaller, less than 3 cm in height, as f. minima (Beck) Kükenthal. He found plants on Southampton Island with the branches of the inflorescence more lastingly erect than in the typical form, and the pistillate spikes bearing generally more numerous and more densely clustered flowers, and he named these specimens var. porsildiana Polunin. Neither name has been widely taken up.

Ball (2002, p. 476) stated that ‘the status of C. krausei is far from clear, and many authors have treated it as a variant of C. capillaris. None of the morphologic characters by which they are distinguished appear to be reliable, and the relationship between chromosome number and morphology is based on examination of relatively few populations. The relationship is further confounded by C. boecheriana Á. Löve, D. Löve and Raymond, which is morphologically similar to C. krausei but cytologically closer to C. capillaris. There is no evidence of an ecologic difference between C. capillaris and C. krausei across its range; C. krausei appears to be sympatric with C. capillaris.

Elven et al. (2003) considered that C. krausei is easily recognised by its bisexual apical spike (female at apex, male at base) and by its more numerous and well-separated female spikes, which when fully developed are long-linear (and not elliptic-ovate as in C. capillaris). The dull brown colour of the bracts and perigynia also differs from the colours of races of C. capillaris. Löve et al. (1957) separated several taxa within C. krausei as considered here, mainly based on ploidy differences. The assignment of chromosome numbers to taxa is still very uncertain.

Subspecies krausei is widely amphi-Beringian (Russian Siberia, Russian Far East, Alaska, and Canada). Subspecies porsildiana occurs in the amphi-Atlantic areas (Iceland, Norway, Canada, and Greenland). Subspecies robustior is reported for the Yukon Territory (Porsild and Cody 1980). If the taxon is divided, plants from Alaska-Yukon and Central Canada would be probably classified as C. krausei subsp. krausei; those from the West Hudson Bay area and Baffin-Labrador area probably referred to C. krausei subsp. porsildiana; and those from Greenland to the latter taxon or to C. boecheriana.

Illustrations. • Habitat. Foreground left, small pale yellow-green plant growing on bare ground among willows. Nunavut, Southampton Island, Coral Harbour, beside grave yard. Aiken and Brysting 01–082. CAN. • Close-up of plant. Left, plant of Carex capillaris subsp. fuscidula. Right, plant of Carex membranacea. Both at the early stages of flowering. Plants growing in dry tundra near a steam. Nunavut, Baffin Island, Iqaluit. 6 July, 2004. Aiken and LeBlanc 04–011. CAN 586484. • Close-up of inflorescence. Bract associated with the base of the inflorescence sheathless, leaf-like, somewhat remote and shorter than the apex of the inflorescence. Inflorescence a panicle of 4, well-separated long linear spikes (a contrast with the elliptic-ovate spikes in Carex capillaris). Note conspicuous pedicels, the terminal spike staminate at the base, and dull pale brown perigynia and floral bracts. Nunavut, Victoria Island, Wollaston Peninsula. CAN 489228. • Close-up of terminal spike. Staminate flowers at the base of the terminal spike with anthers 1.3–1.5 mm long. Floral scales shorter than the mature perigynia, tawny with the margins and the midvein paler in colour than the adjacent body, a contrast with C. capillaris where the midvein is not pale. Stigmas 3 per style. Perigynium apices beaked with a "short" beak 0.3–0.7 mm long. Nunavut, Victoria Island, Wollaston Peninsula. CAN 489228. • Close-up of perigynia. Close-up of glabrous perigynia with three stigmas. Aiken and Brysting 01–082. CAN. • Close-up of flowering plant. Plants from the northernmost known locality, a very isolated site for this disjunct basiphilous arctic sedge. Norway, Svalbard, James I Land, Kapp Waern, Stjerthogda Mountain. August 1996. Photograph by R. Elven. Voucher in O. See also Elven et al., Blyttia 59: 186–189 (2001). • 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.