Dupontia fisheri R. Br. s.l.
Poaceae, grass family.
Chlor. Melvill. 33: 1823.
Type: Canada. Melville Island, 1820, Mr. (G.) Fisher on Parry's first voyage. (Holotype: BM! Isotype: LE, Tzvelev, 1976).
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!).
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!).
Vegetative morphology. Plants perennial herbs; 6–50 cm high (-80 cm high on Southampton Island: see image library). Ground-level or under-ground stems horizontal; rhizomatous, or stoloniferous (horizontal stems sometimes above ground, especially in tidal zones); elongate, or compact; 1–3 mm wide. Scales present; smooth; 3–23 mm long (often poorly preserved); glabrous. Aerial stems erect (usually only a single culm per season in the High Arctic); not conspicuously jointed; circular or oval in cross-section; glabrous. Leaves distributed along the stems (but more towards the base of the culm); alternate; simple; marcescent. Petioles absent. Sheaths with the margins fused only in the lower part; glabrous (veins conspicuous); collars present. Ligules present; 0.4–3(–5.5) mm long (short on basal leaves, to 5.5 mm on uppermost culm leaves); membranous, or a fringed membrane; glabrous; transversely oblong; apices truncate; erose, or lacerate. Blades 10–130 mm long; 0.5–2 mm wide (folded width). Blades appressed to the stem, or spreading; folded in bud; linear; folded, or 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. Blades adaxial surface glabrous. Blades abaxial surface glabrous.
Reproductive morphology. Flowering stems present. Flowering culm nodes rooting at the lower nodes (but not as conspicuous as in plants of Arctophila fulva); not exposed, or becoming exposed; number visible 0–1. Flag leaf sheaths not inflated (somewhat inflated in larger specimens). Inflorescence paniculate (not always fully exserted); diffuse (at anthesis in larger specimens. In smaller High Arctic plants, inflorescences may appear dense and spike-like); lanceolate (to pyramidal); 2–16.5 cm long; 10–60 mm wide; 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 pedicellate; disarticulating above the glumes; laterally compressed; obovate; 4.2–10.4 mm long; 1.4–4.2 mm wide. Florets per spikelet 1–2(–3) (rarely in Canadian plants). 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; oblanceolate; 3.3–10.1 mm long; glabrous; veins 1–3. Rachilla internode 1–1.5 mm long; glabrous (sometimes with a few scabrous trichomes). Rachilla not pronounced between the florets; terminating in a vestigial floret (sometimes), or extending beyond the uppermost floret. Callus differentiated; hairs 1 mm long (approx.); hairs shorter than the floret. Lemma 3.5–6.6 mm long; lanceolate; keeled (slightly); surface dull; surface glabrous, or hairy; veins 3–5. Lemma apex acuminate, or acute; entire; glabrous; awnless, or awned. Awn arising from the tip (if awn is present); 0.1–1(–2.2) mm long (if applicable). Palea well developed; 2.8–6 mm long; with glabrous veins. Perianth reduced to lodicules. Stamens 3. Anthers 1.5–3(–3.7) mm long. Gynoecia superior. Carpels syncarpous; 3. Styles 2. Ovules 1. Fruit sessile. Fruit dry; a caryopsis; indehiscent. Fruit 3–4 mm long. Seeds 1.
Chromosome information. 2n = 42, 44, 66, 84, 88, and 132.
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').
44. - Flovik (1938 Svalbard, 2n = 44+ff,
'psilosantha'); Jørgensen et al. (1958 Greenland,
'psilosantha'); Bowden (1960a northern Canada, 'psilosantha');
Löve and Ritchie (1966 northern Canada, 'psilosantha'); Johnson and
Packer (1968 northwestern Alaska , 'psilosantha'); Löve and
Löve (1975b, 'psilosantha'); Lipkin (1983 Ala,
'psilosantha'); Darbyshire et al. (1992 north eastern Canada, eight
counts, 2n = 44, 44+1B, 'fisheri' coll.).
66. - Lipkin
(1983 Alaska); Brysting et al. (in prep. Svalbard).
84. - Zhukova
(1969 north eastern Asia, 'fisheri'); Engelskjøn (1979 Svalbard,
2n = 80–85, 'fisheri' s.str.); Lipkin (1983 Russia,
'fisheri').
88. - Flovik (1938 Svalbard, 2n = 88+ff,
'fisheri' s.str.); Packer and McPherson (1974 northern Alaska,
'fisheri'); Löve and Löve (1975b, 'pelligera');
Petrovsky and Zhukova (1981 Wrangel Island, 'fisheri'); Brysting et al.
(in prep. northern Canada, 'fisheri' coll.).
132. - Bowden
(1960a northern Canada, 'fisheri' coll.); Löve and Löve (1975b
northern Canada, 'fisheri').
126–132. - Brysting et al. (in
press, northern Canada, 'fisheri' coll.).
Distribution. Northern hemisphere distribution: circumpolar; Greenland, Canada. Arctic. Range in the Canadian Arctic Archipelago widespread. Arctic Islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry Islands, Cornwallis, Banks, Victoria, Prince of Wales, Somerset, King William, Southampton, Coats.
Ecology and habitat. Substrates: wet meadows, around the margins of ponds, depressions of low centre polygons, marshes, along streams, lake shores, tundra (wet), slopes; imperfectly drained moist areas; sand, silt, clay, moss; peat (rarely in bogs). Habitats: a common member of low wetland communities and particularly abundant near lagoons. It is sometimes dominant or co-dominant with Alopecurus borealis.
Taxon as an environmental indicator. 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 favorable microhabitats, this may be indicative of re-growth after grazing by water fowl during the spring.
Notes. Porsild (1964) recognized this taxon and also D. fisheri
subsp. psilosantha (Rupr.) Hultén, that we have placed in synonymy
with D. fisheri at this time. While extreme morphological expressions
occur, there appears to be a continuum of variatioNorth Americaong 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. A
detailed taxonomic study is underway. Initial statistical analyses of the data
do not encourage recognizing taxa within D. fisheri based on
morphological characteristics at this time.
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, the only record of the hybrid was the
type collection (LE) and it is a questionable specimen. All other specimens of
Arctodupontia from the Chukotsk peninsula were re-determined as
Arctophila fulva (R. Elvan, personal communication).
Dupontia
fisheri forms an intergeneric hybrid with Poa labradorica (Darbyshire
et al. 1992). The following observations were made (29 August, 2001) on more
than 20 Dupoa specimens from DAO that were annotated by Cayouette and
Darbyshire between 1986–1994.
Underground Stems: Dupontia
rhizomes have distinct whorls of roots at the nodes, the rhizomes of
Dupoa have few roots given off at any particular node.
Panicle: usually the panicle appears more coarse and dense, and
conspicuously the stigmas, rather than anthers are protruding from the
spikelets.
Spikelets: Dupontia spikelets when purple have the colour
running lengthwise down the spikelet: spikelets of Dupoa are often green
at the base with a purple zone running across the lemmas, similar to the
coloration seen on Poa species. Spikelet lengths 7–10.2 mm.
Floret number: There are often 4 florets in a spikelet and commonly
three. The number of florets per spikelet on a plant is higher and more variable
than that observed for Dupontia.
Glume apices: Dupontia
the glumes are membranous or scarious at the tips where there is a wide
translucent zone. They are often without veins reaching to the tips and the tips
tend to bend, or twist. The glumes of Dupoa are herbacious, opaque, with
only a narrow scarious, translucent zone at the tips that do not twist or bend.
Lemmas: The callus at the base of the lemma in Dupontia
consists of a variable number of stiff hairs. The callus of Dupoa has
similar stiff hairs, but at the mid-vein there is a wooly web similar to that
found in Poa species.
Lemma surface: Dupontia is
described as sometimes having trichomes ot the apex of the lemmas, but in the
over 160 spikelets examined I did not observe this, although I looked for it. I
have described the surface of some Dupontia lemmas as pubescent, i.e.
soft hairs. In Dupoa, the lemmas are sometimes nearly glabrous,
particularly on the third floret or fourth floret. When trichomes are present
they are in stiff lines to the apex of the lemma, and often absent towards the
base of the lemma. The stiffness of the trichomes has lead to them being
described as scabrous.
Illustrations. • Habitat. Plants common in meadow, plants 15 cm tall. Some plants had branches divergent, some with erect branches. Nunavut, Victoria Island, Cambridge Bay. 6 km SE 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. Inflorescence with lowest branches spreading at right angles to the rachis, and a relatively stout culm. Nunavut, Victoria Island, Cambridge Bay. Summer camp across bay, 6 km SE of Flagstaff Point. Common in meadow, plants 15 cm tall. 24 July 1997. L.L. Consaul 1114 and L.J. Gillespie. 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. Photographed 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, 64o08'N, 83o10'W. Aiken and Brysting AB01–020. O. Photographed by Mark Mallory. • Variation in inflorecence shape. 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. Aiken and Brysting AB01–020. O. (Fresh material, photographed in hotel under less than ideal circumstances). • Laboratory photograph. Plant considered "psilosantha-like" because of spreading inflorescence and culm that is approximately twice as wide at the base, as near the inflorescence. Canada. Nunavut, Cornwallis Island, Aiken, 93–080. (CAN). Photographed by G. Steel, August 1993. • 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 Aug. 1920. J. Lid. 449 (confirm. as D. fisheri s.str. R. Elven 23 Mar. 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. Canada: Northern Quebec: Hudson Bay, Cape Henrietta, 18 Aug. 1914, W. Spreadborough, 62740, CAN 513741. Scanned by R. Boles CAN. • Holotype of D. fisheri var. aristida. Type of D. fisheri var. aristida. Canada, Baffin Island, Albert Harbour, Eclipse Sound, 72°42'N, 78°15'W, 14 Aug. 1957, M.O. Malte 118831. Holotype: CAN 36763. Scanned by R. Boles, CAN. • Chromosome voucher. This specimen is the voucher for a chromosome determination of 2n=44 by W.M. Bowden, 1948. The plant was collected in Canada, 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. The plant was collected in Canada, Nunavut, Southampton Island, Coral Harbour, east of Hudson Bay Post. 64°08'N, 83°10'W. W.J. Cody 1929, 8 Aug. 1948. This specimen was considered typical species D. fisheri, W.G. Dore, 1949 and annotated as such by A.E. Porsild, 1950 and 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. It was collected in Canada, Northwest Territories, Arctic Coast, Cape Dalhousie, 70°20'N, 129°55'W, saline marshes and meadows, A.E. and R.T. Porsild, 2700, 7–14 August, 1927, CAN 36750. Left hand plant approx. 53 cm high. • Distribution map.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
