Flora of the Canadian Arctic Archipelago
English: Arctic Kentucky bluegrass,
French: Pâturin des prés,
Inuktitut: Iviit, ivisuka, ivitsuskaka.
Poaceae, Grass family.
Published in Suom. Kasvio 205. 1933.
Type: Norway: Dovre, leg. Blytt 252. Lectotype: UPS E.Fries, Herb. Norm. Fasc. 9, No. 93.
Synonymy. Poa pratensis taxon alpigena Fr. ex Blytt, Norges Fl. 1: 130. 1861. Nom. illeg. superfl. for P. pratensis L. var. iantha Laest.
Poa alpigena Lindm., Sv. Fanerogamfl. 91. 1918.
Vegetative morphology. Plants 4–25 cm high; perennial herbs; not caespitose. Only fibrous roots present. Ground level or underground stems horizontal; rhizomatous (turf forming); elongate, or compact. Aerial stems erect; not filiform. Leaves present; mainly basal; alternate; marcescent. Petioles absent. Sheaths present; with the margins fused only in the lower part; sheath collars present. Ligules present; 0.7–2.2 mm long; membranous; glabrous; ovate-oblong. Ligule apices obtuse; entire. Leaves grass-like. Blades 7–80 mm long, 0.9–1.3 mm wide (when folded), appressed to the stem or spreading, folded in bud, linear, flat or folded (more commonly), veins parallel, midvein similar in size to other veins in the leaf, bulliform cells in distinct rows on either side of the midvein. Blade adaxial surface hairy (sparsely puberulent). Blade abaxial surface glabrous.
Reproductive morphology. Flowering stems circular or oval in cross section. Flowering stems with leaves; culm nodes not exposed. Inflorescences paniculate; pyramidal; 1.6–5.5 cm long; 5–20 mm wide. Inflorescences main axis glabrous. Inflorescence primary branches 2–16 mm long; glabrous; with appressed secondary branches, or with spreading secondary branches. Spikelets disarticulating above the glumes; 3.8–5.8 mm long; 1.6–3.5 mm wide. Florets per spikelet 2–3(–5). Two glumes present. First glume 0.85–0.9 × the length of the second glume; 0.45–0.55 × spikelet length; 2.1–2.6 mm long; ovate; glabrous; veins 1–3; apex acute. Second glume 0.4–0.9 × as long as the spikelet; almost as long as, or longer than, the lowest floret (or barely as long); 2.4–3 mm long. Second glume ovate. Second glume glabrous; veins 3. Rachilla not pronounced between the florets; extending beyond the uppermost floret; internode 0.5–0.9 mm long; internode glabrous. Callus differentiated (sparsely lanate); hairs shorter than the floret. Lemma ovate, or lanceolate; 2.7–3.8 mm long; keeled (slightly); surface dull; surface hairy (on margins and along keel, elsewhere glabrous); veins 5; apex acute, or rounded; apex entire; awnless. Palea well developed; 2.5–3.2 mm long; veins scabrous. Flowers bilaterally symmetrical (zygomorphic). Perianth represented by lodicules. Stamens 3. Anthers 1.4–1.7 mm long. Ovary superior; carpels 3; syncarpous. Ovaries glabrous. Styles 2. Placentation basal. Ovules per ovary 1. Fruit sessile; a caryopsis; indehiscent. Seeds 1.
Chromosome information. 2n = 37–56.
2n = about 37. Hedberg (1967, northern Canada);
2n (6x) = 42. Zhukova and Petrovsky (1976, 1980, western Chukotka);
2n = 42. Petrovsky and Zhukova (1981, Wrangel Island);
2n = 51+5ff. Flovik (1938, Svalbard);
2n (8x) = 56. Zhukova (1967a, 1968, northeastern Asia); Zhukova and Petrovsky (1976, 1980, western Chukotka); Zhukova et al. (1977, northeastern Asia).
Ploidy levels recorded 6x/8x.
Ecology and habitat. Substrates: hummocks, around the margins of ponds, tundra, slopes, dry meadows, flood plains; imperfectly drained moist areas, dry, moderately well-drained areas; gravel, sand, silt. Occurring on moist to well-drained, often disturbed sites, such as creek flood plains, on damp silt, marshy depressions among polygons, or plateaus of clay and silt. The subspecies is also found on gravel ridges along beaches, on damp sand near the sea shore, down slope from bird perches, and at Thule sites. Porsild (1957, 1964) considered the taxon occasional to common in sandy tundra, in meadows by streams and lake shores where it often forms a firm mat. He stated it is strongly nitrophilous and greatly favoured by refuse and manure near human habitation or below bird cliffs and nesting sites.
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 islands: Baffin, Ellesmere, Axel Heiberg, Parry islands (Bathurst, Emerald, Lougheed, Melville, Prince Patrick), Cornwallis, Banks, Victoria, Prince of Wales, Somerset, Southampton, Coats (Ellef Ringes, Mill, and Prince Charles Islands and Melville Peninsula).
Northern hemisphere distribution. Circumpolar, or circumboreal. Northern Iceland, Northern Fennoscandian, KaninPechora, Svalbard Franz Joseph Land, Polar Ural Novaya Zemlya, YamalGydan, Taimyr Severnaya Zemlya, AnabarOlenyok, Kharaulakh, YanaKolyma, 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 taxon is distinct and relatively common in the eastern Canadian High Arctic. It has a chloroplast DNA haplotype that is distinct from that of the southern subsp. pratensis (Gillespie and Boles 2001). It was treated as a full species Poa alpigena by Porsild (1955) and Edmondson (1980) and as a subspecies by Tzvelev (1976). Porsild (1955) claimed that Canadian specimens agreed well with specimens from northeastern Greenland and also with the excellent description and illustrations given by Scholander (1934).
Elven et al. (2003) noted that most taxa of the P. pratensis aggregate are more or less apomictic with both agamospermy and bulbil propagation (many studies from Müntzing 1932, 1940 onwards). Some reticulation is at least probable, and the limits between entities (agamospecies) are often unclear. There are several bulbil-reproducing plants in the 'alpigena' affinity. In Svalbard and Greenland, several biotypes of subsp. alpigena (described as var. vivipara) are much more common than is subsp. colpodea. In the Canadian Arctic viviparous plants of subsp. alpigena have been observed on Melville Island, but are generally less common and widespread than subsp. colpodea.
Illustrations. • Habitat: Baffin Island, Cape Dorset. Plants near marker, growing close to the beach as indicated by Leymus in the background. Nunavut, Baffin Island, Cape Dorset. 4 August, 2005. Aiken. No voucher. • Habitat: Ellesmere Island, Ridge Lake. Plant growing on a south-facing slope at the north side of a lake. Nunavut, Ellesmere Island, Fosheim Peninsula, Ridge Lake, 79°56.36'N, 84°37.99'W. 5 August, 1999. L.J. Gillespie 6638, L.L. Consaul and R.J. Soreng. CAN. • Beach habitat: Baffin Island, Cape Dorset. Lush, isolated, blue-green grass beside the marker, growing in Puccinellia phryganodes meadow on beach. Nunavut, Baffin Island, Cape Dorset. 2 August, 2005. Aiken. No voucher. • Plant in saline habitat: Baffin Island, Cape Dorset. Lush, isolated, blue-green grass beginning to flower. Nunavut, Baffin Island, Cape Dorset. 2 August, 2005. Aiken. No voucher. • Close-up of plant. Rhizomatous plants growing on a dryas-willow slope. Nunavut, Axel Heiberg Island, Expedition Fiord, McGill University field camp, 79°24'N, 90°48'W. 1 August, 1999. L.J. Gillespie 6550 and L.L. Consaul. CAN. • Close-up of plant. Rhizomatous plants with inflorescences at anthesis. Note the spreading branches. Nunavut, Axel Heiberg Island, Fossil Forest, Geodetic Hills, 79°54.67'N, 89°00.88'W. 4 August, 1999. L.J. Gillespie 6591, L.L. Consaul and R.J. Soreng. CAN. • Vegetatively proliferating inflorescence. Vegetatively proliferating inflorescence after growing in the greenhouse in Ottawa for about a week. Plants had been brought in from Nunavut, Cornwallis Island, Resolute Bay, Thule site. Aiken 94–015. • 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..