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 spicata (L.) DC.

English: Spiked wood rush,

French: Luzule en épi,

Inuktitut: Iviit, ivisuka, ivitsuskaka.

Juncaceae, Rush family.

Published in In Lam. and DC. Fl. Franc., éd. 3, 1: 161. 1805.

Synonymy. Juncus spicatus L., Sp. Pl. 330. 1753.

Vegetative morphology. Plants (5–)15–35 cm high; perennial herbs; caespitose. Only fibrous roots present. Base thick extending 1–8 cm into the soil. Ground level or underground stems absent. Aerial stems erect. Leaves mainly basal (but also present on the flowering stems); alternate; marcescent. Petioles absent. Sheaths present; sheath throats densely hairy. Ligules absent. Leaves grass-like. Blades 10–80 mm long, 0.7–2.8(–3.5) mm wide, straight, linear, flat or channelled, veins parallel. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blade margins with non-glandular hairs (white, simple and unbranched); apices acuminate (involute).

Reproductive morphology. Flowering stems circular or oval in cross section. Flowering stems with leaves. Leaf or reduced bract subtending the base of the inflorescence present; reduced, or scale-like; shorter than the apex of the inflorescence (narrow and leafy); without calloused tip. Inflorescences head-like, or a spike of spikes (dense, nodding, made up of several short spikes, aggregated to form a continuous or basally interrupted compact unit); dense; 0.5–1.5 cm long. Pedicels absent (flowers born in the axils of whitish, lacerated bracts). Individual spike(s) pendent (inflorescence on a long peduncle). Floral bracts apices lacerate (margins ciliate, the cilia may appear as fine curly hairs). Flowers per inflorescence 20–80; small (subtending bracts as long or longer than the flowers). Sepals conventional (brown tepals); 3; free; (2–)2.5–3(–4) mm wide; brown (with clear margins, or very pale throughout); scarious; non-accrescent. Calyx tip mucronate (the midvein running to the very tip as with a true awn); glabrous. Petals conventional (brown tepals); free; same length as the calyx (or slightly shorter); 3; brown (scarious); lanceolate (with stiffly pointed tips); (2–)2.5–3 mm long (shorter than the outer whorl). Stamens 6. Anthers 0.5–0.7 mm long. 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 (pale to dark or blackish); 1.3–1.6 mm long; 1–1.3 mm wide (intact capsules); not distinctly flattened; dehiscent. Seeds 3; 1.3–1.6 mm long (including caruncle about 0.2 mm long); brown; surfaces smooth.

Chromosome information. 2n (2x) = 12. Nordenskiöld (1951); Michalska (1953, central Europe); Quézel (1957, northwestern Africa); Favarger (1965, central Europe); Druskovic (1995, southeastern Europe):

2n = 14. Chrtek and Krisa (1962, Europe);

2n (4x) = 24. Böcher (1938a); Sørensen and Westergaard in Löve and Löve (1948, Greenland?); Nordenskiöld (1949, 1951, 1953); Löve and Löve (1956, Iceland; 1966b), Löve (1981d, central Canada); Jørgensen et al. (1958, Greenland); Knaben and Engelskjøn (1967, Norway); Pojar (1973, western Canada). Several more southern counts.

2n = 36 (6x). Contandriopoulos and Gamisans (1974, southern Europe).

Ploidy levels recorded 2x/4x.

Ecology and habitat. Substrates: slopes (grassy), cliffs; dry; rocks, gravel (dry sunny slopes like the southfacing slope near Apex, Baffin Island, or rocky slopes such as gull cliffs); with low organic content, with high organic content; nitrophilous. Arctic Island records describe the habitat as dry grassy slopes and gull cliffs.

North American distribution. Alaska, Yukon, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago limited. Uncommon. Low Arctic (Northernmost record: Nunavut, Baffin Island, Beekman Peninsula, 63°24'N, 64°40'W (CAN 283999)). Arctic islands: Baffin.

Northern hemisphere distribution. Circumpolar, or circumboreal (very disjunctly arctic-alpine, non-arctic in most of Asia). Northern Iceland, Northern Fennoscandian, Kanin–Pechora, Polar Ural – Novaya Zemlya, Central Canada, Labrador – Hudson Bay, West Greenland, East Greenland.

General notes. Polunin (1940) observed that although this species is very variable elsewhere, it seems relatively constant in the Canadian Arctic, although it varies considerably in size and luxuriance and there is some variation in the numbers of cilia on the bracts. Elven et al. (2003) consider the taxon very homogeneous throughout the Arctic but very heterogenous in more southern temperate mountains.

Chrtek and Krísa (1962) reported on a taxonomic study of the species Luzula spicata (L.) D.C. sensu lato in Europe.

Illustrations. • Close-up of inflorescences. Head-like inflorescences that characteristically nod. They are made up of several short spikes aggregated to form a continuous or basally interrupted compact unit, subtended by a narrow leaf-like bract. Aiken and LeBlanc 04–099. CAN 586571. • Close-up of inflorescence. Several heads of flowers, each subtended by bracts with ciliate margins. Tepals brown, lanceolate, tipped with an awn-like bristle; inner whorl equaling or slightly longer than the broadly ovate, brown or blackish capsules. Aiken and LeBlanc 04–099. CAN 586571. • Pressed specimen. Tufted plant with head-like inflorescences. Nunavut, Baffin Island, Kimmirut. August, 2005. Annie Archambault AA293. CAN 586935. • Close-up of inflorescence. Bract subtending the inflorescence is shorter than the inflorescence. Tepals have long awn-like bristles. Annie Archambault, 264, Aug. 2005. Nunavut, Baffin Island, Kimmirut. CAN. 586979. • 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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