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

Poa abbreviata R. Br.

English: Short bluegrass,

French: Pâturin court,

Inuktitut: Iviit, ivisuka, ivitsuskaka.

Poaceae, Grass family.

Published in Chlor. Melvill. 29. 1823.

Type: Canada. Melville Island, Mr. (Rev. G.) Fisher, on W.E. Parry's first voyage, 1819–1820. Holotype: BM!

Vegetative morphology. Plants 5–15(–20) cm high; perennial herbs; caespitose (often forming very compact tussocks, branching intravaginal). Only fibrous roots present. Ground level or underground stems absent. Aerial stems erect. Leaves mainly basal; alternate; marcescent. Prophylls 11–15 mm long; with scabrous veins (minute trichomes); with pronounced keels (as pronounced as in the 2-keeled palea). Petioles absent. Sheaths present; with the margins fused only in the lower part (1/10 to 1/4); glabrous; sheath collars present. Ligules present; 0.4–0.7(–3) mm long; membranous; glabrous; lanceolate. Ligule apices acute; lacerate. Leaves grass-like. Blades 10–70 mm long, 0.4–0.7 mm wide (when rolled), appressed to the stem, folded in bud, linear, folded (usually, rarely flat), veins parallel, midvein similar in size to other veins in the leaf, bulliform cells in distinct rows on either side of the midvein (relatively small cells). Blade adaxial surface glabrous. Blade abaxial surface glabrous.

Reproductive morphology. Flowering stems two or more per plant. Flowering stems circular or oval in cross section. Flowering stems with leaves; culm nodes not exposed. Flag leaf sheaths inflated (flag leaf blade appressed to the stem). Inflorescences paniculate; dense; linear, or lanceolate (ellipsoid, sometimes scarcely exserted above the uppermost culm leaf); (0.5–)1.2–2.2 cm long; 4–10 mm wide (about twice as long as broad). Inflorescences main axis glabrous. Number of inflorescence branches at lowest node 1–3. Inflorescence primary branches 2–8 mm long; glabrous; with appressed secondary branches. Spikelets disarticulating above the glumes; ovate; (3–)4.5–7.1 mm long; 1.5–3.3 mm wide (at anthesis). Florets per spikelet 2–4(–5). Two glumes present. First glume 0.85–1 × the length of the second glume; 0.6–0.7 × spikelet length; 3–4.6 mm long; lanceolate; glabrous; margins glabrous; veins 1 (glumes often purple tinged with hyaline margins); apex acuminate, or acute. Second glume 0.4–0.9 × as long as the spikelet; almost as long as, or longer than, the lowest floret; 3.4–4.6 mm long. Second glume lanceolate, or ovate. Second glume glabrous; veins 3. Rachilla not pronounced between the florets; extending beyond the uppermost floret; internode 1 mm long (approximately); internode glabrous. Callus differentiated (rarely, as a vestige of a web, slightly separated from the appressed tuft of hairs at the base of the lemma), or not differentiated; hairs 0.3 mm long (approximately); hairs shorter than the floret. Lemma lanceolate; (2.5–)3.6–4.6 mm long; keeled (laterally compressed but not strongly keeled); surface dull (apical margins thinner in texture than the body of the lemma); surface hairy (the lower half of the lemma is covered with dense, short appressed hairs on and between the veins); veins 5 (or 4, not reaching the apex); apex truncate (obliquely); apex entire; awnless. Palea well developed; 2.8–3.2 mm long; veins scabrous. Flowers bilaterally symmetrical (zygomorphic); bisexual. Perianth represented by lodicules. Sepals modified (but not a pappus). Stamens 3. Anthers (0.2–)0.6–1.2 mm long. Ovary superior; carpels 3; syncarpous. Ovaries glabrous. Styles 2. Placentation basal. Ovules per ovary 1. Fruit sessile; dry; a caryopsis; 1.4–1.6 mm long; indehiscent. Seeds 1.

Chromosome information. 2n = 28 and 42.

2n (4x) = 28. Sokolovskaya and Strelkova (1960);

2n (6x) = 42. Holmen (1952, Greenland); Jørgensen et al. (1958, Greenland); Mosquin and Hayley (1966, northern Canada); Hedberg (1967, northern Canada); Zhukova (1968, northeastern Asia); Zhukova et al. (1973, north and northeastern Asia; Petrovsky and Zhukova (1981, Wrangel Island);

Tzvelev (1976) reported three ploidy levels, 2n = 28 (4x), 42 (6x), and 70 (10x). Only the hexaploid chromosome number (2n = 42) has been repeatedly confirmed on checked vouchers. The tetraploid number is not entirely impossible and has tentatively been included above. The decaploid reports (Flovik 1938, Sokolovskaya 1955) are very suspect and have not been accepted. Flovik's report, as 2n = about 76 (11-ploid), was found by Sørensen to be based on a Svalbard specimen of P. arctica (Elven, personal communication, 1999).

Ploidy levels recorded 4x/6x.

Taxon as an environmental indicator. Plants usually grow in relatively isolated clumps, behaving as early colonisers of weakly to moderately alkaline silt and sand. They provide nurse crop shelter for other larger species that eventually outcompete them in establishing ground cover.

Ecology and habitat. Substrates: hummocks, along streams, river terraces, lakeshores, tundra, slopes, ridges (including marine reworked moraines, drumlins, and beach ridges), dry meadows (grass, dwarf shrub - legume, or saxifrage barrens or plains); imperfectly drained moist areas (occasionally), dry, moderately well-drained areas; acidic (weakly), or calcareous (weakly to moderately). Often growing near the sea as on the beach ridges near the shoreline at the Thule site, Resolute Bay, Cornwallis Island. Found in moist to well drained, weakly to moderately alkaline silt and sand tills, and on highly weathered Palaeozoic rocks. Occasionally found in dwarf shrub or Saxifraga oppositifolia barrens. It is locally abundant around bird perches and animal burrows.

North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut. Range in the Canadian Arctic Archipelago widespread. Common. High Arctic. Arctic islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry islands (Bathurst, Eglington, Loughead, Meigen, Melville, Prince Patrick), Cornwallis, Banks, Victoria, Somerset (Amund and Ellef Ringnes).

Northern hemisphere distribution. Circumpolar. Svalbard – Franz Joseph Land, Polar Ural – Novaya Zemlya, Taimyr – Severnaya Zemlya, Kharaulakh, West Chukotka, Wrangel Island, East Chukotka, West Alaska, North Alaska – Yukon, Central Canada, Labrador – Hudson Bay, Ellesmere Land – Peary Land, West Greenland, East Greenland.

General notes. There has been constant agreement that this is a distinct species (Porsild 1964, Edmondson 1980, Tzvelev 1976). All specimens examined from the Canadian Arctic Islands belong to subsp. abbreviata (Soreng, personal communication, 1991). A second subspecies, P. abbreviata subsp. pattersonii (Vasey) A. and D. Löve and Kapoor, is found in northwestern North America, but has not been found on the Canadian Arctic Islands. Tzvelev (1976) also recognised subsp. jordalii (A.E. Porsild) Hultén, but this subspecies is now considered a synonym of P. abbreviata subsp. pattersonii (Vasey) A. and D. Löve and Kapoor, by Soreng (1991).

Illustrations. • Three grasses at Eureka. Three grasses growing close together on a clay substrate as indicated: Poa hartzii (near knife), Poa abbreviata (right, top) and Puccinellia angustata (right, bottom). Nunavut, Ellesmere Island, Eureka weather station. August, 1991. Aiken. • Habitat. Plants growing among rocks on a yellowish calcareous silty till. Nunavut, Ellesmere Island, near John Richardson Bay, 8021'N, 7121'W. Aiken 98–049. Photograph by Mollie MacCormac. Scale bar in cm. • Plant habit. Plant approximately 10 cm high growing among rocks on a yellowish calcareous silty till. Nunavut, Ellesmere Island, near John Richardson Bay, 8021'N, 7121'W. Aiken 98–049. Photographed by Mollie MacCormac. Scale bar in cm. • Albino plant habit. Left, plants approximately 5–6 cm high with albino inflorescences. Nunavut, Cornwallis Island, Resolute Bay, Thule site. Aiken 94–014. CAN. Photographed by H. Gibbins. • Contrasting colour morphs. Contrasting colour forms that had been collected within 3 m of each other held side by side. Left, albino inflorescences. Right, more characteristic inflorescences that are usually reddish purple. Aiken 94–014. CAN. Photographed by H. Gibbins. • Close-up of inflorescence. Spikelets tend to be plump, have glumes that are more than half the length of the spikelet but are approximately equal in width. These spikelets are post-anthesis and have a few dehisced anthers exposed. Scale bar in cm. Photographed by Mollie MacCormac. • Type specimen. N.W.T., Melville Island. 1819–1820. Mr. (Rev. G.) Fisher on W.E. Parry's first voyage. (Holotype: BM). • 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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