Flora of the Canadian Arctic Archipelago
| Flora of the Canadian Arctic Archipelago | |
Poaceae, Grass family.
Published in Syst. Veg. 2: 686. 1817.
Type: Northern Sweden: Torne Lappmark, Mt. Njuolja, 25.07.1950, leg. N.D.Simpson 50133, selected by Cope in Cafferty et al., Taxon 49: 293. 2000. Neotype: BM.
Synonymy. Aira alpina L., Sp. Pl. 65. 1753.
Deschampsia cespitosa (L.) P. Beauv. subsp. alpina (L.) Tzvel., in Fed., Fl. Evrop. Chasti SSSR 1: 209 1974, is an illegitimate homonym according to Soreng et al. (2003), because there is an earlier heterotypic var. alpina (from central Europe, probably an occasionally sprouting D. cespitosa s.s.). This is according to ICBN (2000).
Vegetative morphology. Plants 10–15(–17) cm high; perennial herbs; caespitose; sometimes vegetatively proliferating in inflorescences. Only fibrous roots present. Roots white. Ground level or underground stems absent. Aerial stems erect. Leaves mainly basal; alternate; marcescent. Prophylls 1.5–2 mm long; with scabrous veins; with pronounced keels. Petioles absent. Sheaths present; persisting; forming a conspicuous build-up at the base of the plant; greyish brown (straw-coloured); with the margins fused only in the lower part; glabrous; sheath collars present. Ligules present; 1.5–4.5 mm long; membranous; lanceolate. Ligule apices acuminate; entire. Leaves grass-like. Blades 50–80 mm long, 0.5–1.5 mm wide, spreading, rolled in bud, linear, involute, veins parallel, midvein similar in size to other veins in the leaf, without bulliform cells in a distinct row on either side of the midvein. Blade adaxial surface scabrous. Blade abaxial surface glabrous. Blade margins glabrous (to the naked eye, minutely scaberulous at 40×).
Reproductive morphology. Flowering stems circular or oval in cross section. Flowering stems about as high as the leaves, or conspicuously taller than the leaves; with leaves; culm nodes not exposed. Flag leaf sheaths inflated. Inflorescences with bulbils; paniculate; dense; lanceolate; 4–10 cm long; 20–40 mm wide. Inflorescences main axis glabrous. Number of inflorescence branches at lowest node 2–4. Inflorescence primary branches 20–40 mm long; glabrous; with spreading secondary branches. Spikelets disarticulating above the glumes; lanceolate (with spreading leaves); 6–15 mm long; 2–7 mm wide (based on width of spreading leaves). Florets per spikelet 0 spikelets vegetatively proliferating. Two glumes present. First glume 0.9–1 × the length of the second glume; 0.8–1 × spikelet length; 5–5.5 mm long; margins glabrous; apex acuminate. Second glume 0.4–0.9 × as long as the spikelet (depending on development of the bulbil); shorter than the lowest floret; 6.2–6.8 mm long. Second glume lanceolate. Second glume glabrous; veins 3. Rachilla not pronounced between the florets; extending beyond the uppermost floret; internode 0.1–0.8 mm long (sometimes extended beyond the bulbil); internode glabrous. Callus differentiated. Lemma lanceolate; 6.5–7 mm long; rounded on the back; surface shiny; surface glabrous; veins 5; apex acuminate; apex entire; apex glabrous; awnless, or awned (vestigial). Awn arising from the tip (if applicable). Awn 0–4 mm long. Palea vestigial, or absent; 0–0.5 mm long (often absent). Flowers bilaterally symmetrical (zygomorphic); asexual. Perianth represented by lodicules (absent in proliferating spikelets). Stamens present, or absent (sometimes aborted anthers present); 0–3. Anthers splitting longitudinally (if applicable). Anthers usually not developed. Ovary superior. Styles present (rarely if at all), or absent; 2. Ovules per ovary 1 (rarely applicable). Fruit not developed.
Chromosome information. 2n = 26–56.
2n (2x to about 4x) = 26–56.
2n = 26, 39, 48, 52. Nygren (1949, northern Europe);
2n = 26, 38–39. Sokolovskaya and Strelkova (1960);
2n = 29 49–52. Albers (1980);
2n = 35–38. Sokolovskaya (1955);
2n = 39 + 3 – 4ff, 49. Engelskjøn and Knaben (1971, northern Norway);
2n = 39, 41, 49. Flovik (1938, 1940, Svalbard);
2n = 39, 52. Löve and Löve (1956, Iceland);
2n = 49. Maude (1939, Britain);
2n = 49, 56. Hubbard (1954, Britain);
2n = 49, 49 + 2B. Jørgensen et al. (1958, Greenland);
2n = 50. Engelskjøn (1979, Bear Island);
2n = 52. Böcher and Larsen (1950, Greenland);
2n = 56. Hagerup (1939, northern Europe).
Ploidy levels recorded 2x-4x.
Ecology and habitat. Substrates: rocks and gravel; with low organic content; calcareous (decomposed schist, granite, and limestone, CAN 33148).
North American distribution. Nunavut Islands, northern Quebec (?), Labrador. Range in the Canadian Arctic Archipelago limited. Rare. Low Arctic. Arctic islands: Baffin (Resolution Island off the south tip).
Northern hemisphere distribution. Amphi-Atlantic. Northern Iceland, Northern Fennoscandian, Svalbard – Franz Joseph Land, Polar Ural – Novaya Zemlya, Labrador – Hudson Bay, West Greenland, East Greenland.
General notes. Löve and Löve (1975) 'adjusted' the counts so as to fit a uniformly tetraploid (2n = 52) concept of D. alpina, while they indicated that plants counted under this name, but with 2n = 26 and 39, could be hybrids. As seen from the above, the 2n = 52 counts are in the minority. In northern Norway and Svalbard, plants that fit the diagnostic characters of D. alpina are counted with 2n = about 39, 41, 49, and 50, and in several of these areas there is no possibility of (recent) hybridisation, as this is the only Deschampsia present. The uniformly tetraploid chromosome number of the Löves that should characterise this species is therefore unknown from what is the type area of D. alpina (northern Fennoscandia, "Lapponia"). This does not exclude that the entire 'species' is an old hybrid complex, probably involving D. cespitosa, that has turned to vivipary. The few diploid counts of 2n = 26 may originate from occasionally vegetatively proliferating D. cespitosa s.s. and not from D. alpina.
This amphi-Atlantic bulbil-reproducing entity differs from D. cespitosa (D. cespitosa subsp. cespitosa) in other characters besides the production of bulbils and is morphologically separable from the occasional vegetatively proliferating forms of subsp. cespitosa. If the taxon is shown to be an autopolyploid derivative of subsp. cespitosa it might be better treated as a subspecies of D. cespitosa, as done by Tzvelev (1976) and Clarke (1980). However, if the taxon is shown to be an alloploid, D. brevifolia might be the other parent (Elven et al. 2003).
Illustrations. • Habitat. Tufted grass plants growing on gravel. Norway, Mt. Thom. 11 September, 2000. Aiken and Elven s.n. • Close-up of plant. Plant growing in rock crevice. Norway, Mt. Thom. 11 September, 2000. Aiken and Elven. • Close-up of inflorescence. Inflorescence from specimen collected from the only Canadian arctic island location for the species. Glumes (A) subtend the developing vegetative propagule (B). Nunavut, Resolution Island, Acadia Cove. 27 July, 1937. Wynne-Edwards 7256. CAN. • Close-up of spikelets. Vegetatively proliferating spikelets of D. alpina with the bulbils more developed than in the previous picture. Labrador, Ryan's Bay, tundra above the anchorage. 10 August, 1931. Ernst C. Abbe and M. Odell 81. CAN. • Herbarium specimen. General growth form of this taxon can be seen on this herbarium specimen from Labrador, which is more robust than the specimen collected from the Arctic islands. Note the vegetatively proliferating inflorescence which is typical of this taxon. Labrador, Ryan's Bay, tundra above the anchorage. 10 August, 1931. Ernst C. Abbe and M. Odell 81. 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.
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