Flora of the Canadian Arctic Archipelago
English: Arctic hairgrass, Tufted hairgrass,
Inuktitut: Iviit, ivisuka, ivitsuskaka.
Poaceae, Grass family.
Published in R. Br., Chlor. Melvill. 33. 1823.
Type: Canada. Melville Island, 1819–1820, W. E. Parry. Holotype: K. Two Isotypes: LE. Topotype: DAO!.
Synonymy. Deschampsia cespitosa subsp. brevifolia (R. Br.) Tzvelev, in Fedorov, Fl. Evrop. Chasti SSSR, 1: 141. 1974.
Vegetative morphology. Plants (10–)15–20(–30) cm high; perennial herbs; caespitose. Only fibrous roots present. Ground level or underground stems absent. Aerial stems erect. Leaves mainly basal; alternate; marcescent. Prophylls 20–30 mm long (relatively rare); with hairy veins; with pronounced keels. Petioles absent. Sheaths present; with the margins fused only in the lower part; glabrous; sheath collars present. Ligules present; 1.3–3.1(–5) mm long; membranous; glabrous; ovate-oblong. Ligule apices acuminate, or acute; entire. Leaves grass-like. Blades 5–30(–65) mm long, 0.3–0.8 mm wide (rolled) or 0.5–2.5 mm wide (when flat), appressed to the stem or spreading, rolled in bud, linear, flat (rarely) or folded or involute, veins parallel, midvein similar in size to other veins in the leaf. Blade adaxial surface glabrous or scabrous or hairy (with sparse minute trichomes). Blade abaxial surface glabrous.
Reproductive morphology. Flowering stems circular or oval in cross section. Flowering stems with leaves; culm nodes not exposed, or becoming exposed; culm nodes number visible 0–2. Flag leaf sheaths inflated (slighlty). Inflorescences paniculate; dense, or diffuse (occasionally); lanceolate, or ovate (compact), or pyramidal (spreading in warmer habitats); 1.5–10(–12) cm long; 5–20(–110) mm wide. Inflorescences main axis glabrous, or scabrous. Number of inflorescence branches at lowest node 3–5. Inflorescence primary branches 1–36(–60) mm long; glabrous, or scabrous; with appressed secondary branches, or with spreading secondary branches (less commonly). Spikelets disarticulating above the glumes; ovate to obovate; 2.3–5(–6) mm long; 1.4–4 mm wide. Florets per spikelet 2(–3). Two glumes present. First glume 0.9–1.2 × the length of the second glume; 0.8–1 × spikelet length; 2.7–4 mm long; lanceolate; glabrous; margins glabrous; veins 1; apex acuminate, or acute. Second glume as long or longer than the spikelet; almost as long as, or longer than, the lowest floret; 3–4(–5.4) mm long. Second glume lanceolate, or ovate. Second glume glabrous; veins 3. Rachilla not pronounced between the florets; extending beyond the uppermost floret; internode 0.5–1.6 mm long. Callus differentiated; hairs 0.3–1.5 mm long; hairs shorter than the floret. Lemma oblong, or lanceolate; 2.8–4 mm long; keeled; lemma not strongly inrolled; surface shiny; veins 5 (lateral veins faint); apex acute, or rounded, or truncate; apex erose, or lacerate; apex glabrous; awned. Awn arising from the middle or below (rarely higher up). Awn 1–2.2(–3.5) mm long. Palea well developed; 2.4–3.3(–5) mm long; veins scabrous (trichomes sparse). Flowers bilaterally symmetrical (zygomorphic); bisexual. Perianth represented by lodicules. Stamens 3. Anthers 1.5–2.5 mm long. Ovary superior; carpels 3; syncarpous. Styles 2. Placentation basal. Ovules per ovary 1. Fruit sessile; dry; a caryopsis; elongate-cylindrical; 2.3–3 mm long; indehiscent. Seeds 1.
Chromosome information. 2n = 26 and 52.
2n (2x) = 26. Holmen (1952, Greenland); Jørgensen et al. (1958, Greenland); Bowden (1960b, 1961, northern Canada); Hedberg (1967, northern Canada); Knaben (1968, central Alaska); Mulligan and Porsild (1969, Yukon); Zhukova and Tikhonova (1973, Chukotka); Bowden (1960b); Mulligan and Porsild (1969, on a specimen from the Oglivie Mountains, Yukon). The later authors commented that plants of this species from Southampton Island, Canada, and Greenland have the same chromosome number according to Holmen (1952), Jørgensen et al. (1958), Bowden (1960b), and Hedberg (1967);
2n(4x) = 52. Krogulevich (1986, northern Siberia, Putorana); Petrovsky and Zhukova (1981, Wrangel Island).
Ploidy levels recorded 2x/4x.
Taxon as an environmental indicator. This taxon is indicative of a location that has been recently disturbed, either by the influence of humans or because of natural disturbances characteristic of flood plains, slumping slopes, or frost boils.
Ecology and habitat. Substrates: wet meadows (clayey), marshes (e.g., with Carex aquatilis), along streams, river terraces (in colluvial, fluvial deposits), lakeshores, tundra (furrows, berms and margins of polygons), slopes (often with other grasses, Salix, and Dryas; sometimes in very well-vegetated areas), seashores; imperfectly drained moist areas, dry (Melville, Prince Patrick), moderately well-drained areas; rocks, gravel, sand, silt, clay, till; peat (sometimes); calcareous. Most commonly occurring on recently disturbed silt or clay deposits, such as thaw flow slides, eroding banks, fine-grained floodplains. In wet clay or silt, by river banks or lake shores, on damp but loose calcareous gravel, in small marshy depressions among polygons, on sand, and occasionally in dry tundra, or in the centres of otherwise bare mud-boils. Deschampsia brevifolia also occurs around construction sites and settlements.
In an experiment where 10 plants collected on Ellesmere Island, at Eureka, were moved to a transplant garden in the grounds of Nunavut Arctic College, Iqaluit, the plants struggled for a few years and then died out. Plants of this species are common in disturbed areas around Nettilling Lake, and often eaten by geese. Re-growth after such grazing may result in a mat of plants 1–2 cm high that have been mistaken for Puccinellia phryganodes.
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut. Range in the Canadian Arctic Archipelago widespread. Common. Arctic. Arctic islands: Baffin, Ellesmere, Axel Heiberg, Parry islands, Cornwallis, Banks, Victoria, Prince of Wales, Somerset, Southampton, Coats (Ellef Ringnes).
Northern hemisphere distribution. North American, or Siberian. Taimyr Severnaya Zemlya, AnabarOlenyok, Kharaulakh, YanaKolyma, 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 was considered part of a D. cespitosa complex by Kawano (1963, 1966) who investigated the cytogeography and evolution of members of the complex from many parts of the world, including the Canadian Arctic. He reported on the hypothetical relationships of members of the D. cespitosa complex, with chromosome numbers ranging from 2n = 26, 28, 35, 38, 39, 41, 49, 52, to 56 and noted that Tateoka (1955) and Bowden (1960b) had reported the existence of B or supernumerary chromosomes in D. cespitosa.
Porsild (1964) recognised D. cespitosa (now considered an excluded taxon) and three other taxa within the genus Deschampsia, i.e., D. alpina, D. brevifolia, and D. pumila (see D. sukatschewii (Popl.) Roshev. subsp. borealis (Trautv.) Tzvelev).
Aiken et al. (1995) attempted to follow Porsild (1957) and recognise both D. cespitosa subsp. cespitosa and D. cespitosa subsp. brevifolia. Further field work has established that there is a single, phenotypically plastic taxon in the Canadian Arctic, similar to the type recognised by Robert Brown from Melville Island as D. brevifolia. The taxa D. cespitosa s.s. and D. glauca, as understood in northern Europe, probably do not occur in the Canadian Arctic unless they have been introduced (Elven, personal communication, 2005).
The phenotypic plasticity in this taxon was observed in plants transplanted from Eureka Sound, Ellesmere Island (80°09'N, 86°00'W), in 1990, to Iqaluit, Baffin Island (64°44'N, 68°28'W), and Ottawa, Ontario (45°18'N, 75°50'W). Over a 3-year period the plants grown in Iqaluit became smaller and more stunted. Many of the 10 plants grown in Ottawa died, but the one illustrated in the image library became larger and with more diffuse inflorescences as photographed in 1994. In the photograph, the previous seasons inflorescence as seen in the straw has tightly appressed branches, the 1994 inflorescences have spreading branches. The voucher for the original collection is of a plant approximately 16 cm high, whereas the voucher for the photograph in the image library is a plant 32–33 cm high and documents the phenotypic plasticity expressed.
The very short awn is sometimes absent or broken and often overlooked, resulting in small specimens being misidentified as Poa species.
Illustrations. • "Cultivated" plant. Plants brought from Ellesmere Island in 1991 and grown in Ottawa for three years. Panicles diffuse, probably because they are at anthesis. Note compact inflorescence of previous season's growth, and extensive branching 1994's inflorescences. • "Cultivated" plant, close-up of inflorescence at anthesis. Plants brought from Ellesmere Island in 1991 and grown in Ottawa for three years. At anthesis. Photographed in 1994. • Type specimen. Duplicate type, mistakenly marked Dupontia. Collected on Capt. W.E. Parry's First Voyage and described by Robert Brown. N.W.T., Melville Island. 1819–20. Sabine, Edwards, Ross et. al. 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..