Flora of the Canadian Arctic Archipelago

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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

Luzula confusa Lindeberg

English: Northern wood rush,

French: Luzule trompeuse,

Inuktitut: Malikkaanujaq (Baffin Island); Iviit, ivisuka, ivitsuskaka (Nunavik).

Juncaceae, Rush family.

Published in Bot. Not. 1855: 9. 1856.

Synonymy. Luzula arcuata Sw. subsp. confusa (Lindeb.) A. Blytt and O.C. Dahl, sine basionimo, Haandb. Norges Fl. 201. 1903.

Vegetative morphology. Plants 5–30 cm high; perennial herbs; caespitose (loosely). Only fibrous roots present. Ground level or underground stems horizontal (not always present on specimens); rhizomatous; compact. Aerial stems erect. Leaves mainly basal; alternate; marcescent (persisting for many years). Petioles absent. Sheaths present; reddish orange. Ligules absent. Leaves grass-like. Blades 15–60 mm long, 0.6–2 mm wide (reddish). Leaves not filiform (sometimes very narrow). Blades straight, linear, channelled and involute or flat (less commonly), veins parallel. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blade margins with non-glandular hairs (sparse, or almost lacking, white, simple and unbranched); apices acuminate (involute).

Reproductive morphology. Flowering stems squarish in cross section (terete, with undulating margins in cross section). Flowering stems with leaves (usually 2–3 leaves, 1.5–8 cm long). Leaf or reduced bract subtending the base of the inflorescence present; conspicuous and leaf-like, or reduced, or scale-like (rarely longer than the inflorescence); shorter than the apex of the inflorescence (and scale-like). Inflorescences head-like, or a raceme of spikes (flowers in 2–7 clusters that are occasionally sessile, but often with lateral clusters on spreading branches 1–4 cm long); dense (within the heads), or diffuse (in the arrangement of the heads); 0.5–5 cm long; 5–30 mm wide. Pedicels absent. Individual spike(s) erect, or ascending. Floral bracts apices lacerate (membranous with hairy margins). Flowers per inflorescence 20–80; small. Sepals conventional (brown tepals); 3; free; 1.6–2.6 mm wide; brown; scarious. Calyx glabrous. Petals conventional (brown tepals); free; same length as the calyx; 3; brown (with a clear apex); ovate, or lanceolate; unlobed; 1.8–2.2 mm long (inner whorl shorter than calyx whorl). Stamens 6. Anthers 0.5–0.9 mm long (about 2 times the filament length). Ovary superior; carpels 3; syncarpous. Styles 3; free. Stigmas per ovary 3. Ovules per ovary 3. Fruit sessile; with calyx persisting; dry; a capsule; ovoid; brown (dark); 1.3–1.7(–2.8) mm long; 0.9–1.1 mm wide (intact capsules); not distinctly flattened; dehiscent. Seeds 3; 0.9–1.1(–1.6) mm long; brown; surfaces hairy (with a tuft of fine, tangled hairs).

Chromosome information. 2n = 36 (6x). Böcher and Larsen (1950, Greenland); Holmen (1952, Greenland); Löve and Löve (1966b, northeastern USA); Löve (1981d, northern Canada); Mosquin and Hayley (1966, northern Canada); Zhukova (1967a, northeastern Asia); Johnson and Packer (1968, northwestern Alaska); Packer and McPherson (1974, northern Alaska); Zhukova and Petrovsky (1976, western Chukotka); Yurtsev and Zhukova (1978, eastern Chukotka); Petrovsky and Zhukova (1981, Wrangel Island);

2n = 48 (8x). Sørensen and Westergaard in Löve and Löve (1948, Greenland); Löve and Löve (1956, Iceland), not included by Löve and Löve (1975).

Several of the chromosome counts listed by Löve and Löve (1975) should be checked against original publications and vouchers. They might have been sorted on taxa (L. confusa and L. arcuata s.s.) according to the belief in a constant ploidy difference. Such a difference is improbable. The ones listed above are only those that were published as L. confusa. Engelskjøn (1979) found mainly 2n = 36 in Norwegian material of both 'arcuata' s.s. and 'confusa', with a "single, aberrant count" (Knaben 1950) of 2n = 48 in an otherwise 2n = 36 population. (Elven, in Elven et al. 2003).

Ploidy levels recorded 6x.

Ecology and habitat. Substrates: wet meadows (usually around the drier edges), hummocks (often Dryas), snow patches (occasionally), around the margins of ponds, depressions of low-centre polygons, along streams (sometimes in dry streambeds), lakeshores, tundra, ridges (often on old beaches, gullies, moraines or rock outcrops), seashores; imperfectly drained moist areas (towards the outer edges, with L. nivalis growing in wetter areas, e.g., on Melville Island), seepage slopes, dry, moderately well-drained areas (more commonly); rocks, gravel (often on beaches), sand, till, moss; with low organic content, with high organic content, peat; acidic (found on weakly acidic sandstone, granite and sand), or calcareous. Often described as locally abundant; "ubiquitous- one of the commonest plants everywhere" (CAN 283994).

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, alpine. Arctic islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry islands, Cornwallis, Banks, Victoria, Prince of Wales, Somerset, Southampton, and Coats (as well as Ellef Ringnes, Amund Ringnes, Air Force, Ward Hunt, Winter, Lougheed, Mackenzie King, Cameron, Meighen, Nottingham, and Digges Islands).

Northern hemisphere distribution. Circumpolar, or circumboreal (arctic-alpine). 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, Wrangel Island, South Chukotka, East Chukotka, West Alaska, North Alaska – Yukon, Central Canada, Labrador – Hudson Bay, Ellesmere Land – Peary Land, West Greenland, East Greenland.

General notes. The combination L. arcuata subsp. confusa was not formally made by Blytt (1861 p. 298), just cited in synonymy with reference to Hartman, but there with sufficient citation of basionym to be considered validly published (Elven et al. 2003).

Bliss and Svoboda (1984), in a study of soils, plant communities, and net annual plant production in the western Queen Elizabeth Islands, recognised a Luzula confusa graminoid steppe that was more productive than a Puccinellia barren. Bell and Bliss (1978) estimated that the roots of L. confusa live 7–13 years. Addison and Bliss (1984) reported on the adaptations of Luzula confusa to a polar semi-desert environment.

Van der Wal et al. (2000) manipulated the plant phenology of Luzula heathland plots in Spitsbergen (78°N) by adding or removing snow, which altered the time for plots (2 m × 2 m; n = 10) to become snow-free. Nitrogen content of the forage species decreased with time after snowmelt, whereas C:N ratio increased. Manipulation of snowmelt led to a shift in "phenological time", without altering these plant quality parameters as such. Early in the growing season, Svalbard reindeer (Rangifer tarandus platyrhynchus) selected the advanced plots which had been snow-free for longest, presumably because of the greater biomass of both Luzula confusa and Salix polaris, major components of reindeer diet at that time of the year. Phenolic content did not differ among treatments, and is therefore unlikely to play a role in reindeer selection for plots with early snowmelt. Unlike in temperate regions, where selection for plant quality seems to be of major importance, selection for plant quantity might be an outcome of generally low levels of plant biomass and high forage quality during the growing season in the High Arctic. Reindeer selection for high plant biomass is likely to lead to a more favourable nitrogen and energy return than selection for high plant quality.

Nakatsubo et al. (1998), as a part of the study on soil carbon flow in a deglaciated area in Svalbard (79°N), estimated the contribution of the belowground respiration of vascular plants, including Luzula confusa, to total soil respiration in August 1996. The respiratory activity and the Q10 value of the respiration were higher in S. polaris than in the other two species. Total soil respiration rates measured in the field varied widely. The areas with dense vegetation cover tended to show high respiration rates. The contribution of the belowground respiration to total soil respiration was negligible in the early stages of succession. On the other hand, the respiration of the belowground parts contributed to a significant proportion (approx. 29%) of the total soil respiration in the latter stages of succession.

Illustrations. • Habitat. Plants growing in dry stony tundra. Nunavut, Baffin Island, Iqaluit. 25 August, 1997. Aiken 97–034. CAN. • Habitat. Plants growing near the markers on dry somewhat ericaceous tundra. Nunavut, Baffin Island, Ogac Lake. 13 July, 2004. Aiken and LeBlanc 04–083. CAN 586555. • Close-up of rhizomatous base of plant. Base of plant rhizomatous. Basal scales of the culms with reddish tinge. Nunavut, Ellesmere Island, Tanquary Fiord. CAN 455115. • Transition between leaf sheath and blade. Transition zone between leaf blade and glabrous sheath. Note long scattered hairs on the margin and a tuft of hairs at the transition zone. Hairs on leaf margins are characteristic of species in the genus Luzula. Nunavut, Baffin Island, Iqaluit. July, 2004. Photographed by LeBlanc. • Inflorescence with receptive stigmas. Compact inflorescences with three receptive stigmas per flower. Nunavut, Baffin Island, Ogac Lake. 13 July, 2004. Aiken and LeBlanc 04–083. CAN 586555. • Close-up of inflorescence. Compact arctic island inflorescence with floral bract apices lacerate and long ciliate. Nunavut, Melville Island, Beverly Inlet. 14–15 August, 1999. Elven RE2914/9. CAN 583366. • Inflorescence with two clusters of flowers. Two spikes showing flowers with brown, pointed tepals. Note the developing pale yellow anthers and three white, sometimes translucent, stigmas per flower. Nunavut, Baffin Island. Aiken 2002. No voucher. • Close-up of plant: drawing. Plants with relatively narrow leaves when compared with Luzula nivalis. Drawing by Mrs. S. Bergh and Mrs. L. Barstad based on herbarium specimen. Svalvard, Oscar II Land Isfjorden, Kapp Bohenman. 29 August, 1924. J. Lid. O-209095. With permission of the Botanical Museum, University of Oslo, Norway. • Close-up of inflorescences: drawing. Left, culm with a single inflorescence cluster of more than 20 flowers. Right, culm with two inflorescence clusters of flowers. Drawing by Mrs. S. Bergh and Mrs. L. Barstad based on herbarium specimen. Svalvard, Oscar II Land Isfjorden, Kapp Bohenman. 29 August, 1924. J. Lid. O-209095. With permission of the Botanical Museum, University of Oslo, Norway. • Close-up of inflorescence: drawing. Inflorescence with four clusters of flowers. Drawing by Mrs. S. Bergh and Mrs. L. Barstad based on herbarium specimen. Svalvard, Sørkapp Land, Bjørneinflyane. 5 August, 1924. J. Lid 238. O-209055. With permission of the Botanical Museum, University of Oslo, Norway. • 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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