Flora of the Canadian Arctic Archipelago
English: Dwarf hairgrass,
French: Deschampsie naine,
Inuktitut: Iviit, ivisuka, ivitsuskaka.
Poaceae, Grass family.
Published in Novosti Sist. Vyssh. Rast., 32: 182. 2000.
Type: Northern Siberia: "Ad fl. Taimyr", 1843, leg. Middendorff, selected by Tzvelev, Zlaki SSSR 283. 1976. Lectotype: LE.
Synonymy. Aira cespitosa L. var. borealis Trautv., Trudy Imp. S.-Peterburgsk. Bot. Sada 1: 86. 1871.
Deschampsia borealis (Trautv.) Roshev., in Kom., Fl. URSS 2: 246, 750. 1934.
Deschampsia cespitosa (L.) P. Beauv. subsp. borealis (Trautv.) Á. Löve and D. Löve, Opera Bot. 5: 65. 1961.
Deschampsia pumila (Griseb.) Ostenf., Meddel. Grønl. 64, 6: 169. 1923. non (Steven ex Westb.) Fomin and Woronow 1907.
Deschampsia paramushirensis Honda, J. Fac. Sci. Univ. Tokyo (Bot.) 3, 1: 140. 1930.
Deschampsia cespitosa (L.) P. Beauv. subsp. paramushirensis (Honda) Tzvelev, Zlaki SSSR 283. 1976.
Deschampsia sukatschewii (Popl.) Roshev. subsp. minor (Kom.) Tzvelev, in Tolm., Fl. Arct. URSS 2: 85.1964.
Vegetative morphology. Plants 10–27 cm high; perennial herbs; caespitose. Only fibrous roots present. Ground level or underground stems absent. Aerial stems erect. Leaves mainly basal; alternate; marcescent. Prophylls 10–20 mm long; with scabrous veins; lacking pronounced keels. Petioles absent. Sheaths present; with the margins fused only in the lower part; glabrous; sheath collars present. Ligules present; 1.2–3.5 mm long; membranous; glabrous; lanceolate. Ligule apices acuminate, or acute; entire. Leaves grass-like. Blades 10–50 mm long, 0.8–1.3 mm wide (when rolled), spreading, rolled in bud (but the very pronounced ribs may cause them to appear as folded), linear, folded, 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 scabrous. 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 0–1. Flag leaf sheaths not inflated. Inflorescences paniculate; diffuse; pyramidal; 4.5–6 cm long; 15–60 mm wide. Inflorescences main axis glabrous. Inflorescence primary branches 18–60 mm long; glabrous; with spreading secondary branches. Spikelets disarticulating above the glumes; oblong; 3.9–4.8 mm long; 1.1–2.3 mm wide. Florets per spikelet 2, or 3. Two glumes present. First glume 0.8–0.9 × the length of the second glume; 0.7–0.85 × spikelet length; 2.7–4 mm long; lanceolate; 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; 3.4–4.5 mm long. Second glume lanceolate. Second glume glabrous; veins 3. Rachilla pronounced between the florets; extending beyond the uppermost floret; internode 1–1.5 mm long; internode hairy. Callus differentiated; hairs 1.2–1.4 mm long; hairs shorter than the floret. Lemma oblong; 2.8–3.2 mm long; rounded on the back; surface shiny; surface glabrous; veins 5; apex rounded, or truncate; apex erose; apex glabrous; awned. Awn arising from the middle or below. Awn 1.6–2.5 mm long. Palea well developed; 2.5–2.9 mm long; veins glabrous. Flowers bilaterally symmetrical (zygomorphic). Perianth represented by lodicules. Stamens 3. Anthers 1.5–1.8 mm long. Ovary superior; carpels 3; syncarpous. Ovaries glabrous. Styles 2. Placentation basal. Ovules per ovary 1. Fruit sessile; dry; a caryopsis; indehiscent. Seeds 1.
Chromosome information. 2n = 26, 28, 36, 38, and 39.
2n (2x) = 24-26-28. Holmen (1952, Greenland); Jørgensen et al. (1958, Greenland); Hagerup in Jørgensen et al. (1958, Greenland); Zhukova (1965a, eastern Chukotka, 2n = 28, 1969, northeastern Asia; 1982, northeastern Asia); Sokolovskaya and Probatova (1975, 2n = 24–26); Yurtsev and Zhukova (1978, eastern Chukotka, for D. komarovii); Zhukova (1980, southern Chukotka, for D. komarovii); Zhukova and Petrovsky (1980, western Chukotka); Engelskjøn (unpublished Svalbard);
2n = 36–38. Yurtsev and Zhukova (1978, eastern Chukotka, 2n = 38, for D. komarovii); Dalgaard (1989, western Greenland);
2n = about 39, Bowden (1960b, from the sand below the high tide mark at Iqaluit, Baffin Island, Canada.);
2n = 39, Böcher and Larsen (1950);
2n = 42. Zhukova et al. (1973, northeastern Asia, for D. komarovii);
2n (4x) = 52. Zhukova (1967a, northeastern Asia); Petrovsky and Zhukova (1981, Wrangel Island, also for D. komarovii); Zhukova and Petrovsky (1980, western Chukotka).
Ploidy levels recorded 2x/4x.
Taxon as an environmental indicator. Mats of this plant are dense and compete well with plants of similar size in damp and somewhat disturbed sites. They are readily out-competed by Arctagrostis latifolia in similarly damp but more stable habitats.
Ecology and habitat. Substrates: wet meadows, marshes, seashores; clay. Forming dense tussocks on damp mud, sand, or gravel by brackish pools or on marshy flats near the tidal high water line. A few plants have been struggling to survive behind the Science Institute of the Northwest Territories building in Iqaluit.
North American distribution. This species is reported in eastern North America, southern Baffin Island, Prince Patrick, and Banks Islands, from Greenland, and northern Quebec, Alaska, Northern Russia, Siberia, and Svalbard. Alaska (?), Yukon (?), Northwest Territories Islands, continental Northwest Territories (?), Nunavut Islands, continental Nunavut (?). Range in the Canadian Arctic Archipelago limited. Uncommon. Arctic. Arctic islands: Baffin, Ellef Ringnes, Parry islands (Prince Patrick), Banks.
Northern hemisphere distribution. Circumpolar. KaninPechora, Svalbard Franz Joseph Land, Polar Ural Novaya Zemlya, YamalGydan, Taimyr Severnaya Zemlya, AnabarOlenyok, 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 was known in Canada as D. pumila (Griseb.) Ostenf. (Porsild 1957, Bowden 1960b, Hultén 1968). Tzvelev (1976) recognised that D. pumila is a later homonym of D. pumila Steven. ex Fomin and Waronow, referable to Catabrosa. He recognised the taxon at the subspecific level of D. cespitosa subsp. paramushirensis, distinguishing it from D. cespitosa subsp. borealis Hultén (1968), and he placed the name D. borealis (Trautv.) Roshev. into synonymy under D. pumila. A comparison of characters from Canadian and Eurasian specimens, considered to be this taxon, is given in McLachlan et al. (1989), Table 2.
The combination D. sukatschewii (Popl.) Roshev subsp. borealis (Trautv.) Tzvelev was published by Tzvelev (2000). The Panarctic Flora project Elven et al. (2003) suggests that North American plants assigned to this species may belong to two subspecies, a seashore or coastal plant that is different from a more northern arctic 'moss cushion'. It is possible that in Canada there is an eastern Arctic taxon, subspecies borealis, and a western Arctic taxon D. sukatschewii (Popl.) Roshev. subsp. orientalis (Hultén) Tzvelev.
Elven examined specimens from the Canadian Arctic Archipelgo (May 2005) and concluded that those from the eastern and western islands are all subsp. borealis.
Illustrations. • Habitat: Dorset. Plants near the marker. Plants form tight reddish green cushions with small leaves. Common near the seashore in the Valley suburb. Growing with Carex glareosa. Nunavut, Baffin Island, Cape Dorset. 5 August, 2005. Aiken 05–091. CAN 586961. • Habitat: Dorset. Plants with very short leaves near the marker and in the immediate foreground, growing with Juncus castaneus in moist run-off gravel beside the road. Nunavut, Baffin Island, Cape Dorset. 3 August, 2005. Aiken 05–084. CAN 586955. • Close-up of blue-green plant. Isolated clump growing beside a road and very probably moved to this position with gravel used to repair the roadside. Plants form tight cushions with small leaves. Deep blue-green colour probably reflects the influence of nutrients in the runoff water. Common near the seashore in the Valley suburb. Nunavut, Baffin Island, Cape Dorset. 5 August, 2005. Aiken. No voucher. • Close-up of reddish plants. Reddish plants with very short leaves growing in the saline meadow. Nunavut, Baffin Island, Cape Dorset. 3 August, 2005. Aiken 05–084. CAN 586955. • Laboratory photograph of whole plant. Plants forming a compact tuft of fine, short leaves less than 5 cm high. Inflorescence branches that compact before anthesis and diffuse during anthesis. Nunavut, Baffin Island, Iqaluit. Aiken 94–021. CAN. Laboratory photograph by K. Clarkin. • Herbarium specimen. Plants with inflorescence branches spreading at right angles to the inflorescence at anthesis. Nunavut, Baffin Island, Apex. 1989. Aiken 89–116. CAN. • 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..