Flora of the Canadian Arctic Archipelago
| Flora of the Canadian Arctic Archipelago | |
English: Fisher's tundra grass,
French: Dupontie de Fisher,
Inuktitut: Iviit, ivisuka, ivitsuskaka.
Poaceae, Grass family.
Published in Chlor. Melvill. 33: 1823.
Type: Canada. Melville Island, 1820, Mr. (G.) Fisher on Parry's first voyage. Holotype: BM! Isotype: LE.
Synonymy. Dupontia psilosantha Rupr., Fl. Samojed. Cisural. (Beitr. Pflanzenk. Russ. Reiches 2) pl. 6. 1845.
Dupontia fisheri f. psilosantha (Rupr.) Polunin, Bull. Natl. Mus. Canada 94 (Biol. Ser. 24): 79. 1940.
Dupontia fisheri subsp. psilosantha (Rupr.) Hultén, Acta Univ. Lund. Ser. 2, 38: 226. 1942. TYPE: USSR: described from Kolgujev, "In litt. austr. ins. Kolgujev," Ruprecht. Holotype: LE!.
Poa (Dupontia) pelligera Rupr., Fl. Samojed. Cisural. 64. 1845.
Dupontia pelligera Rupr. ex Nyman, Consp. Fl. Eur. 808. 1882.
Dupontia fisheri R.Br. subsp. pelligera (Rupr.) Tzvelev, Novosti Sist. Vyssh. Rast. 10: 91. 1973.
Dupontia fisheri var. aristata Malte, in Polunin, Bull. Natl. Mus. Canada 94 (Biol. Ser. 24): 80. 1940. Type: Canada. Nunavut: Baffin Island, Albert Harbour, Eclipse Sound, 14 Aug. 1927. M. O. Malte 118831. Holotype: CAN!
Dupontia fisheri f. micrantha (Rupr.) Polunin, Bull. Natl. Mus. Canada 94 (Biol. Ser. 24): 80. 1940.
Vegetative morphology. Plants 6–50 cm high (-80 cm high on Southampton Island: see image library); perennial herbs. Only fibrous roots present. Ground level or underground stems horizontal; rhizomatous, or stoloniferous (horizontal stems sometimes aboveground, especially in tidal zones); elongate, or compact; 1–3 mm wide. Ground level or underground stems scales present; surfaces smooth; 3–23 mm long (often poorly preserved); glabrous. Aerial stems erect (usually only a single culm per season in the High Arctic). Leaves present; distributed along the stems (but more towards the base of the culm); alternate; marcescent. Petioles absent. Sheaths present; with the margins fused only in the lower part; glabrous (veins conspicuous); sheath collars present. Ligules present; 0.4–3(–5.5) mm long (short on basal leaves, on uppermost culm leaves to 5.5 mm long); membranous, or a fringed membrane; glabrous; transversely oblong. Ligule apices truncate; erose, or lacerate. Leaves grass-like. Blades 10–130 mm long, 0.5–2 mm wide (folded width; longest leaves at the base, a contrast with Arctophila fulva), appressed to the stem or spreading, folded in bud, linear, involute (leaf margins only slightly rolled inwards), veins parallel, midvein conspicuously larger than the lateral veins (usually), bulliform cells in distinct rows on either side of the midvein. Blade adaxial surface glabrous. Blade abaxial surface glabrous.
Reproductive morphology. Flowering stems circular or oval in cross section. Flowering stems with leaves; rooting at the lower nodes (but not as conspicuous as in plants of Arctophila fulva); culm nodes not exposed, or becoming exposed; culm nodes number visible 0–1. Flag leaf sheaths not inflated (somewhat inflated in larger specimens). Inflorescences paniculate (not always fully exserted); diffuse (at anthesis in larger specimens. In smaller High Arctic plants, inflorescences may appear dense and spike-like); lanceolate, or pyramidal; 2–16.5 cm long; 10–60 mm wide. Inflorescences main axis glabrous. Number of inflorescence branches at lowest node 2–3. Inflorescence primary branches 3–30(–75) mm long; glabrous; with appressed secondary branches, or with spreading secondary branches. Spikelets disarticulating above the glumes; obovate; 4.2–10.4 mm long; 1.4–4.2 mm wide. Florets per spikelet 1–2(–3) (rarely in Canadian plants). Two glumes present. First glume 0.75–0.85 × the length of the second glume; 0.6–1 × spikelet length; 2.8–7.9 mm long; oblanceolate; glabrous; margins glabrous (glumes and lemma with wide hyaline margins); veins 1–3; apex acuminate, or obtuse, or truncate. Second glume as long or longer than the spikelet; almost as long as, or longer than, the lowest floret; 3.3–10 mm long. Second glume oblanceolate. Second glume glabrous; veins 1–3. Rachilla not pronounced between the florets; terminating in a vestigial floret (sometimes), or extending beyond the uppermost floret; internode 1–1.5 mm long; internode glabrous (sometimes with a few scabrous trichomes). Callus differentiated (usually; often inconspicuous in plants from southern Baffin Island); hairs 1 mm long (approx.); hairs shorter than the floret. Lemma lanceolate; 3.5–6.6 mm long; keeled (slightly); surface dull; surface glabrous, or hairy; veins 3–5; apex acuminate, or acute; apex entire; apex glabrous; awnless, or awned. Awn arising from the tip (if awn is present). Awn 0.1–1(–2.2) mm long (if applicable). Palea well developed; 2.8–6 mm long; veins glabrous. Flowers bilaterally symmetrical (zygomorphic); bisexual. Perianth represented by lodicules. Stamens 3. Anthers 1.5–3(–3.7) mm long. Ovary superior; carpels 3; syncarpous. Ovaries glabrous. Styles 2. Placentation basal. Ovules per ovary 1. Fruit sessile; dry; a caryopsis; 3–4 mm long; indehiscent. Seeds 1.
Chromosome information. 2n = 42, 44, 66, 84, 88, and 126–132.
2n = 42. Sokolovskaya and Strelkova (1941, northern Russia, Kolguev, 'fisheri'; 1960, northern Russia, 'fisheri'; 1962); Zhukova (1966, Chukotka, Wrangel Island, 'psilosantha'); Sokolovskaya and Probatova in Tzvelev (1976, Russia, Siberia, 'psilosantha'); Yurtsev and Zhukova (1978, eastern Chukotka, 'psilosantha'); Engelskjøn (1979, Bear Island, 'psilosantha'); Petrovsky and Zhukova (1981, Wrangel Island, 'psilosantha'); Lipkin (1983 Chukotka, 'psilosantha');
2n = 44. Flovik (1938, Svalbard, 2n = 44 + ff, 'psilosantha'); Jørgensen et al. (1958, Greenland, 'psilosantha'); Bowden (1960b, northern Canada, 'psilosantha'); Löve and Ritchie (1966, northern Canada, 'psilosantha'); Johnson and Packer (1968, northwestern Alaska, 'psilosantha'); Löve and Löve (1975, 'psilosantha'); Lipkin (1983, Alaska, 'psilosantha'); Darbyshire et al. (1992, northeastern Canada, eight counts, 2n = 44, 44 + 1B, 'fisheri' coll.);
2n = 66. Lipkin (1983, Alaska); Brysting et al. (2003, 2004) Svalbard);
2n = 84. Zhukova (1969, northeastern Asia, 'fisheri'); Engelskjøn (1979, Svalbard, 2n = 80–85, 'fisheri' s.s.); Lipkin (1983, Russia, 'fisheri');
2n = 88. Flovik (1938, Svalbard, 2n = 88 + ff, 'fisheri' s.s.); Packer and McPherson (1974, northern Alaska, 'fisheri'); Löve and Löve (1975, 'pelligera'); Petrovsky and Zhukova (1981, Wrangel Island, 'fisheri'); Brysting et al. (2004, northern Canada, 'fisheri' coll.).
2n = 132. Bowden (1960b, northern Canada, 'fisheri' coll.); Löve and Löve, in Löve (1975a, northern Canada, 'fisheri');
2n = 126–132. Brysting et al. (2004, northern Canada, fisheri').
Ploidy levels recorded 4x/6x/8x.
Taxon as an environmental indicator. This taxon is indicative of wet or at least damp, water-retaining environments. This taxon varies in height with degree - growing days and nutrient levels in the microhabitat. When plants form small inflorescences in otherwise favourable microhabitats, this may be indicative of re-growth after grazing by water fowl during the spring.
Ecology and habitat. Substrates: wet meadows, around the margins of ponds, depressions of low-centre polygons, marshes, along streams, lakeshores, tundra (wet), slopes (often near the sea); imperfectly drained moist areas; sand, silt, clay, moss; peat (rarely in bogs). A common member of low wetland communities and particularly abundant near lagoons. It is sometimes dominant or co-dominant with Alopecurus.
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. Arctic islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry islands (Emerald, Melville, and Prince Patrick), Cornwallis, Banks, Victoria, Prince of Wales, Somerset, King William, Southampton, Coats (Digges, Nottingham Islands, Boothia and Melville peninsulas).
Northern hemisphere distribution. Circumpolar. 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. The genus Dupontia R. Br. was named "in honour of Monsieur Dupont, of Paris, author of a valuable essay on the sheaths of the leaves of grasses, and observations on the genus Atriplex". The species name fisheri "was that of Mr. Fisher, whose herbarium contained the most complete series of specimens of this grass" (Brown 1823). The type was collected on Melville Island, Canadian Arctic Archipelago. In 1841, Dupontia fisheri var. flavescens Hooker and Arnott was recognised. It had yellow anthers and was based on a specimen from Kotzebue Sound, Alaska (Hooker and Arnott 1841). This taxon name does not appear to have been used since then. Poa (Dupontia) psilosantha Rupr. and P. (Dupontia) pelligera Rupr. were recognised by Ruprecht (1846). The former has been recognised as a species, D. psilosantha (Rupr.) Griseb.; a subspecies, D. fisheri subsp. psilosantha (Rupr.) Hultén; a variety, D. fisheri var. psilosantha (Rupr.) Trautv.; and a forma, D. fisheri f. psilosantha (Rupr.) Polunin. The latter has been recognised as a species, D. pelligera (Rupr.) Á. Löve and Ritchie; a subspecies, D. fisheri subsp. pelligera (Rupr.) Tzvel.; and a variety D. fisheri var. pelligera (Rupr.) Trautv. When Ruprecht (1846) described D. pelligera he commented that "whether this is D. fisheri R.Br. without comparative original specimens I scarcely dare to decide". He had not seen the Robert Brown type that was collected from the Canadian Arctic Archipelago.
Holm (1907) recognised D. micrantha Holm, claiming that it was readily distinguished from D. fisheri and D. psilosantha by the small size of the spikelets and very narrow leaves. He based his description on material from Halton, Labrador (collected by Waghorne, CAN 36774), and Cape Henrietta, Hudson Bay, northern Quebec (Cape Henrietta, collected by Spreadborough, CAN 513741).
Polunin (1940) commented that many authors had pointed out the impossibility of keeping D. psilosantha as a distinct species and reduced the taxon to a forma. He admitted that the type material of D. fisheri has the glumes more or less obtuse and the lemmas hairy at the base, and that plants assigned to psilosantha are strikingly different 'at least in their extreme development'. Polunin (1940) also noted that in 1936, during numerous field observations in the Eastern Arctic, he had found such a great range of variation, even in closely contiguous plants in the same stand, that he concluded 'Holm's plant is a mere forma depauperata' and generally the result of 'a competition effect'. He reduced the taxon to D. fisheri f. micrantha (Holm) Polunin. He observed what he considered to be a striking aristate form geographically delimited in the Eastern Arctic. It had been named provisionally, on herbarium material, by Malte before he died, and was formally recognised by Polunin (1940) as D. fisheri var. aristata Malte ex Polunin.
Porsild (1964) recognised this taxon and also D. fisheri subsp. psilosantha (Rupr.) Hultén, which we have placed in synonymy with D. fisheri. While extreme morphological expressions occur, there appears to be a continuum of variation among Canadian specimens.
The characters used to separate subspecies in northern Europe and Russia, e.g., shape of glumes, number of florets per spikelet, lemma hairiness, and anther length, do not align consistently among North American samples (Brysting et al. 2003).
Brysting et al. (2003) studied the genus Dupontia from herbarium specimens, including types and chromosome vouchers, by numerical taxonomy, mapping the distribution of morphological characteristics, consideration of chromosome numbers, and field work in the Canadian Arctic. They concluded that morphological characters, used in the literature to divide the genus Dupontia into more than one taxon, cannot be reliably applied to distinguish most North American plants. In North America, we might see two endpoints, which correspond, more or less, to D. psilosantha and D. fisheri, respectively, as these two are recognised in the floras of, for instance, Greenland and Svalbard. However, as suggested by Polunin (1940), there appears to be a continuum of variation among North American specimens and too many intermediate forms that exist, which are impossible to place in two or three categories. Even though only a limited sample of Eurasian specimens were included in the analyses, there is no reason to believe that the inclusion of more specimens from this part of the Arctic will change this conclusion. On the contrary, the continuity in measurements will probably be even more evident. Until further evidence is available, Brysting et al. (2003, 2004) suggest that the genus is treated as monotypic.
Molecular evidence supports the use of a wide species concept (Brysting et al. 2004). DNA sequence data (trnL-trnF, ITS; including plants from Russia, Svalbard, Canada, and Alaska) revealed almost no variation within Dupontia. Only a couple of base pair changes, which were related neither to ploidy levels nor to geography, were found. DNA fingerprinting analysis (AFLP, Amplified Fragment Length Polymorphism) sorted the Dupontia material first of all according to geography (Russia, North America, and Svalbard). Within each geographical region, there was a tendency for plants that were sorted according to ploidy level, suggesting that the ploidy levels have most likely arisen several times within the arctic area.
Two main ploidy levels have been reported in the literature and associated with different taxa: 2n = 42, 44 (4x) and 2n = 84, 88 (8x). The variation in chromosome numbers within each ploidy level is probably the result of B-chromosomes, which are obviously present in these plants (Flovik 1938).
Two counts of 2n = 132 have previously been reported from Arctic Canada, Southampton Island, and Devon Island (Bowden 1960b, Löve and Löve, in Löve 1975a). Results from recent chromosome counts and flow cytometry (Brysting et al. 2004) have revealed that this high ploidy level (2n = 126–132) is widely distributed in Arctic Canada and Alaska and mainly associated with tall, coarse plants with more or less spreading branches. Löve and Ritchie (1966) assigned the three ploidy levels to three different species: D. psilosantha was considered a tetraploid with 2n = 44, D. pelligera an octoploid with 2n = 88, and D. fisheri a decaploid with 2n =132. However, Lipkin (1983) identified D. fisheri subsp. fisheri with the octoploid cytotype (2n = 88), the type material of which is from Melville Island, Canadian Arctic Archipelago. This is in agreement with recent chromosome counts of 2n = 88 for plants from Prince Patrick Island, which are morphologically inseparable from the type material (Brysting et al. 2004).
Tzvelev (1976) reported that "The affinity of the genera Arctophila and Dupontia, is confirmed by the existence of the sterile hybrid ?Arctodupontia scleroclada (Rupr.) [Tzvelev (1973), Novosti Sist. Vyssh. Rast. 10: 91]. = Poa scleroclada Rupr. described from the Malaya Zemlya tundra, but recently also found on the Chukotsk Peninsula]." On the basis of spikelet structure, it occupies an intermediate position between the parental genera. However, in Feb. 1999, in a survey of candidate specimens at LE, all specimens of Arctodupontia from the Chukotsk Peninsula were redetermined as Arctophila fulva.
Illustrations. • Habitat. Plants 15 cm tall, common in meadow. Some plants had divergent inflorescence branches, others had erect branches. Nunavut, Victoria Island, Cambridge Bay, 6 km southeast of Flagstaff Point. 24 July, 1997. L.L. Consaul 1114 and L.J. Gillespie. CAN. • Habitat. Plants lush and abundant near the edge of a wet meadow, some to 80 cm tall. Plant between the markers has a compact panicle. Nunavut, Southampton Island, Coral Harbour, near fuel tank farm. Aiken and Brysting 01–059. CAN. • Close-up of plant. Anne Brysting with a plant 80 cm high collected from habitat in previous picture. 01–059. CAN. • Variation in plant height. Series of plants representing a range in plant height (10–80 cm) collected within a mosaic of micro-habitats in an imperfectly drained area. Nunavut, Southampton Island, Salliq (Coral Harbour), near the fuel tank farm. Aiken and Brysting AB01–019. O. Photograph by Mark Mallory. • Variation in inflorescence appearance. Series of plants representing a range in panicle appearances (from compact to spreading with reflexed branches) collected within a mosaic of micro-habitats in an imperfectly drained area. Nunavut, Southampton Island, Salliq (Coral Harbour), near the fuel tank farm, 64�08'N, 83�10'W. Aiken and Brysting AB01–020. O. Photograph by Mark Mallory. • Laboratory photograph. Plant considered "psilosantha-like" because of the lowermost spreading inflorescence branch and culm that is approximately twice as wide at the base as near the inflorescence. Nunavut, Cornwallis Island. August, 1993. Aiken 93–080. CAN. Photograph by G. Steel. • Close-up of inflorescence. Inflorescence with appressed branches. Spikelets near anthesis, some with the lemma and palea widely separated. Nunavut, Baffin Island, Iqaluit. August, 2005. Photograph by Kathy Thornhill. Aiken 05–075. CAN 586947. • Close-up of inflorescence. Drawing by Mrs. S. Bergh and Mrs. L. Barstad based on a collection from Svalbard, Oscar II Land, Kapp Boheman. 29 August, 1920. J. Lid. 449 (confirmed as D. fisheri s.s., R. Elven, 23 March 1992). O 205843. With permission of the Botanical Museum, University of Oslo, Norway. • Isotype specimen. Culm with compact inflorescence and no base to the plant. Nunavut, Melville Island, Winter Harbour. 1819–20. Collected by Mr. Fisher on Parry's first voyage. Isotype: GH. • Lectotype specimen. Culms with leaves distributed up the stems and inflorescences with short branches. Nunavut, Melville Island, Winter Harbour. 1820. Collected by Mr. Fisher on Parry's first voyage. Lectotype: BM. Selected by J. Cayouette, 1993. • Holotype D. psilosantha. Type of Dupontia psilosantha. "Poa (Dupontia!) psilosantha Rupr.; typus! in Beitr. Z Pflanzenk. Russ. Rech. II (1845) 64. Copiose in lotor austr. et bor. occid. ins. Kolgujew; [abundant on the south and northwest shore [litor] of Kolgujew island;]; Herb. Acad. Petrop.; Litt. austral. ins. Kolguew. Dr. Ruprecht." South shore Kolguew island. Holotype: LE. • Holotype D. pelligera. Type of Dupontia pelligera. "Poa (Dupontia) pelligera Rupr.; typus! in Beitr. Z. Pflanzenkun. Russ. Reich. II (1845) 64. Ad proment. Kanin copiosissima et totos plagas obtegens! [very abundant at Kanin promontory and covering whole beaches!]; Herb. Acad. Petrop.; Litt. Oceani glacial. Promont. Kanin. Dr. Ruprecht." Icy ocean shore Kanin promontory. Holotype: LE. • Syntype of D. micrantha. Syntype of D. micrantha. Northern Quebec, Hudson Bay, Cape Henrietta. 18 August, 1914. W. Spreadborough 62740. CAN 513741. • Holotype of D. fisheri var. aristida. Type of D. fisheri var. aristida. Baffin Island, Albert Harbour, Eclipse Sound, 72�42'N, 78�15'W. 14 August, 1957. M.O. Malte 118831. Holotype: CAN 36763. • Chromosome voucher. This specimen is the voucher for a chromosome determination of 2n=44 by W.M. Bowden, 1948. Nunavut, Baffin Island, Iqaluit (Frobisher Bay), 63�45'N, 68�32'W, H.A. Senn s.n. Living plant received Ottawa 24 July, 1948. DAO 68944. Determined as D. fisheri var. aristata Malte by W.G. Dore, 1948 and annotated by him as related to forma psilosantha in 1949. Annotated D. fisheri var. psilosantha, not aristata, A.E. Porsild, 1950, and D. fisheri subsp. psilosantha by W.M. Bowden, 1959. • Chromosome voucher. This specimen is the voucher for a chromosome determination of 2n=132 by W.M. Bowden, 1948. Nunavut, Southampton Island, Coral Harbour, east of Hudson Bay Post, 64�08'N, 83�10'W. 8 August, 1948. W.J. Cody 1929. This specimen was considered typical of D. fisheri (W.G. Dore, annotation on sheet, 1949) and annotated as D. fisheri s.s. by A.E. Porsild 1950 and D. fisheri subsp. fisheri by W.M. Bowden 1959. The tallest culm is approximately 52 cm high. • Large specimen. This specimen is typical of plants that are robust and taller than literature descriptions in 1990. N.W.T., Arctic Coast, Cape Dalhousie, saline marshes and meadows, 70�20'N, 129�55'W. 7–14 August, 1927. A.E. and R.T. Porsild 2700. CAN 36750. Left-hand plant approximately 53 cm high. • 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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