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

Poa glauca Vahl

English: Glaucous bluegrass,

French: Pâturin glauque,

Inuktitut: Kilirnaujait, Iviit, ivisuka, ivitsuskaka.

Poaceae, Grass family.

Published in In Oeder, Fl. Dan. 6, 17: 3, t. 964. 1790.

Type: Norway: "legi in alpibus Norvegiae Valders versus Vang", leg. J.Vahl. Holotype: C.

Synonymy. Poa glauca Vahl var. tenuior Simmons, Vasc. Pl. Fl. Ellesmereland. 162. 1906.

Three syntypes cited by Simmons, p. 164. "var. tenuior South coast: Fram Fjord (1926), Goose Fjord at Midday Knoll (3504 3644)" O.

Vegetative morphology. Plants 7.5–30 cm high; perennial herbs; caespitose (branches arising extravaginally). Only fibrous roots present. Ground level or underground stems absent. Aerial stems erect (usually stiff and glaucous). Leaves mainly basal (relatively few culm leaves, the uppermost well below the middle of the culm), or distributed along the stems; alternate; marcescent. Prophylls 3–8 mm long; with smooth veins; with pronounced keels (weakly), or lacking pronounced keels. Petioles absent. Sheaths present; with the margins fused only in the lower part (1/10–1/4); glabrous; sheath collars present. Ligules present; 1–2 mm long; membranous; glabrous (apex puberulent); ovate-oblong. Ligule apices acute to obtuse (broadly); entire, or erose, or lacerate. Leaves grass-like. Blades 20–55 mm long, 0.5–1 mm wide (folded width), appressed to the stem or spreading, folded in bud, linear, flat or folded (usually tightly so), veins parallel, midvein conspicuously larger than the lateral veins, bulliform cells in distinct rows on either side of the midvein. Blade adaxial surface glaucous, glabrous. Blade abaxial surface glabrous (often glaucous).

Reproductive morphology. Flowering stems circular or oval in cross section. Flowering stems with leaves; not rooting at the lower nodes; culm nodes not exposed. Inflorescences paniculate (usually, sometimes very narrow and reduced to a raceme in dwarfed arctic plants less than 10 cm tall, branches stiffly erect, creating the usually stiff appearance of the panicle of this species; illustrated in the image library); dense; linear, or obovate (spikelets relatively small and bluish on erect or spreading branching); 1–6 cm long; 2–16 mm wide. Inflorescences main axis scabrous. Number of inflorescence branches at lowest node 2. Inflorescence primary branches 3–14 mm long; scabrous (on the angles, rarely nearly smooth); with appressed secondary branches. Spikelets disarticulating above the glumes; ovate; 3.7–6 mm long; 1.2–5.6 mm wide. Florets per spikelet (2–)3. Two glumes present. First glume 0.83–0.96 × the length of the second glume; 0.48–0.75 × spikelet length; 2.7–3.3 mm long; lanceolate; glabrous; margins glabrous; veins (2–)3; apex acute. Second glume 0.4–0.9 × as long as the spikelet; almost as long as, or longer than, the lowest floret; 2.8–4 mm long. Second glume lanceolate. Second glume glabrous; veins 3. Rachilla not pronounced between the florets; extending beyond the uppermost floret; internode 0.8–1.2 mm long; internode glabrous. Callus differentiated (as a tuft, with several curly hairs, 0.2–0.5 mm long, frequently absent); hairs shorter than the floret. Lemma lanceolate; 2.9–4 mm long; keeled (slightly); surface dull (glaucous, with brownish hyaline margins thinner than the body of the lemma); surface hairy; surface with trichomes on veins only (base characteristically with hairs on the keel and marginal veins, frequently with a few short hairs on the intermediate veins and sometimes between them near the base); veins 5 (sometimes 4, lateral veins not extending to the apex); apex acute; apex entire; awnless. Palea well developed; 2.7–3.4 mm long; veins hairy. Flowers bilaterally symmetrical (zygomorphic). Perianth represented by lodicules. Stamens 3. Anthers 1.2–1.5 mm long. Ovary superior; carpels 3; syncarpous. Ovaries glabrous. Styles 2. Placentation basal. Ovules per ovary 1. Fruit sessile; dry; a caryopsis; 1.6–2 mm long; indehiscent. Seeds 1.

Chromosome information. 2n = 42–72.

2n = 42–72 (6x-11x).

2n = 42. Hedberg (1958, northern Britain); Bowden (1961, Alaska, 2 counts); Löve and Löve (1966b, northeastern USA); Mosquin and Hayley (1966, northern Canada); Löve (1981b, central Canada);

2n = 42, 48, 56, and 2n = 62 as P. anadyrica. Zhukova (1969, northeastern Asia);

2n = 42, 49. Krogulevich (1976a, northern Siberia as P. bryophila);

2n = 42, 49, 56, 62. Löve and Löve (1956, Iceland);

2n = 42, 50, 56. Zhukova (1968, northeastern Asia);

2n = 42, about 49, 56. Sokolovskaya and Probatova (1968, northeastern Asia);

2n = 42, 56. Sokolovskaya and Probatova (1973, northeastern Asia); 2n = 42 56, Yurtsev and Zhukova (1982, northern Siberia);

2n = 42, 56, 62. Zhukova et al. (1973, northern and northeastern Asia);

2n = 44, 48–49, 56. Numerous counts of each, Synnestvedt, in Engelskjøn (1979, southern Norway);

2n = about 50. Bowden (1961, Alaska);

2n = 54–56. Laane (1967, northeastern Norway);

2n = 56. Bowden (1961, Alaska, three counts); Holmen (1952, Greenland); Sokolovskaya (1968, northeastern Asia, Koryak); 2n = 56, Zhukova et al. (1977, northeastern Asia);

2n = about 56. Gervais et al. (1999, eastern Canada); Petrovsky and Zhukova (1981, Wrangel Island);

2n = 56, 70. Jørgensen et al. (1958, Greenland); Zhukova (1982, northeastern Asia);

2n = 63. Löve and Löve (1948, northern Europe); Böcher and Larsen (1950, Greenland); Zhukova and Petrovsky (1975, western Chukotka);

2n = 65. âkerberg (1942, northern Europe);

2n = about 70. Hedberg (1967, northern Canada);

2n = 70–72. Flovik (1938, 1940, Svalbard);

Several more southern counts.

Ploidy levels recorded 6x-11x.

Taxon as an environmental indicator. This is an early colonising species of disturbed environments with sandy or gravel substrates that are weakly acidic or alkaline. It forms dense tussocks in the Low Arctic. It provides excellent cover for the establishment of arctic willows that gradually replace the grass, stabilising the environment in the transition to a climax, Low Arctic tundra. Such a transition was observed in the transplant garden of Burt and Joanne Rose, Iqaluit, 1986–1994.

Ecology and habitat. Substrates: hummocks, snow patches, around the margins of ponds, along streams, river terraces, tundra (barrens, and disturbed sites), slopes, ridges, cliffs; imperfectly drained moist areas, dry, moderately well-drained areas; rocks (e.g., talus, sandstone), gravel, sand, silt, clay, till, moss; with low organic content, with high organic content, peat (several collections at CAN were growing on peat); acidic, or calcareous, or nitrophilous. It is an ubiquitous pioneer species that forms large firm tussocks on well-drained, sandy or gravelly terrain, flood plains and beaches. It is common on weakly acidic, and local, on weakly alkaline soils. The most lush growth forms occur around refuse dumps, animal burrows, and disturbed building sites. Very stunted plants about 10 cm tall, with the inflorescence reduced and spike-like, occur in the colder sectors of the Queen Elizabeth Islands.

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 (Eglington, Emerald, Melville), Banks, Victoria, Somerset, Southampton, Coats (Boothia and Melville peninsulas).

Northern hemisphere distribution. Circumpolar, or circumboreal. 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. This is a very widespread species that looks rather different in cold sectors of the Arctic, as stunted plants only reach 10–15 cm high and have a spike-like inflorescence. Caryopses are rarely formed in High Arctic plants because of the short growing season.

Elven et al. (2003) considered that P. glauca is fairly homogeneous in most northern arctic areas. It becomes much more variable further south in the transition from tundra to forest, boreal mountain ranges, and possibly in the amphi-Beringian area. They suggested that much of the variation is probably caused by hybridisation and will be difficult or impossible to classify satisfactorily.

Illustrations. • Habitat: Dorset. Tussocks of blue-green grass with prostrate inflorescences. Nunavut, Baffin Island, Cape Dorset. 4 August, 2005. Aiken. No voucher. • Plants in fall colours. Plant tussocks with vivid blue-green bases to the culms and reddish inflorescences. Nunavut, Baffin Island, Iqaluit, trail to Apex. 17 August, 2006. Aiken. No Voucher. • Close-up of plant. Large, tufted plant in wet silty soil near foot of glacier. Nunavut, Ellesmere Island, Alexandra Fiord. L.J. Gillespie 6172. CAN. • Close-up of plant. This species is often seen with many previous year's leaves and inflorescences persisting surrounding the current year's culms. Nunavut, Ellesmere Island, Lake Hazen. L.J. Gillespie 5764. CAN. • Plant in laboratory. Low Arctic expression of the species. Plants 20–25 cm tall, inflorescence branches spreading 45–60 from the rachis. Nunavut, Baffin Island, Iqaluit. Aiken 94–019. CAN. Photographed by K. Clarkin. • Close-up of inflorescence. Inforescence with spreading, but still loosely erect branches that have five spikelets borne on some branches. Nunavut, Baffin Island, Iqaluit. Aiken 94–019. CAN. Scale bar in cm. • 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.