Carex aquatilis Wahlenb. subsp. stans (Drejer) Hultén
Cyperaceae, sedge family.
Kungl. Svenska Vetensk.-Akad. Handl., ser. 4, 8, 5: 74. 1962.
Nomenclatural section used by Flora of North America project subgenus Carex, sect. Phacocystis Dumortier
Carex stans Drejer, Naturhist. Tidsskr. 3: 40. 1841.
Carex
aquatilis Wahlenb. var. stans (Drejer) Boott, Illustr. Carex 4: 163.
1867.
Carex concolor R.Br., Chloris Melvill. 25. 1823.
Carex
rigida Gooden. var. concolor (R.Br.) Kük. in Engl.,
Pflanzenreich 38.IV, 20: 301.1909
Type: Described from Greenland.
Vegetative morphology. Plants perennial herbs; (5–)15–30(–40) cm high; not caespitose; coarse, and stoloniferous with stiff, smooth or slightly scabrous obtuse-angled culms in loose clusters. Roots pallid-brown. Ground-level or under-ground stems horizontal; rhizomatous, or stoloniferous; elongate. Scales present (light brown and striate). Aerial stems erect, or decumbent (new growth); not filiform; triangular in cross-section (hollow in the centre); glabrous, or sparsely hairy (slightly). Leaves in a basal tuft; simple. Petioles absent. Sheaths persisting (breaking down into fibres after more than a year); forming a conspicuous build up at the base of the plant; brown, or reddish (sometimes pale purplish); collars absent. Ligules present. Blades 30–100(–250) mm long; (0.5–)1.5–4.5 mm wide. Blades straight; linear; flat, or revolute, or folded (loosely); veins parallel; septate nodulose (seen on the adaxial surface at 10X). Blades adaxial surface glabrous. Blades abaxial surface glabrous. Blade margins scabrous (scaberulous at the tip).
Reproductive morphology. Plants monoecious. Flowering stems present. Flowering stems conspicuously taller than the leaves (usually); with leaves; glabrous. Leaf or reduced bract closely associated with the base of the inflorescence present; conspicuous and leaf-like; exceeding the inflorescence; 30–120(–130) mm long; sheathless (the base of the blade may enclose the stem at the node but there is no sheath covering any part of the internode); persistent. Inflorescence spicate; (2–)4–10(–12) cm long; 5–15 mm wide. Pedicels glabrous. Inflorescence multispicate; 2–5 spikes; lateral spikes borne on pedicels. Individual spike(s) ascending. Terminal spike wholly staminate. Cladoprophyll present at the base of the peduncle of lateral spikes. Staminate flowers conspicuous. Floral scales as long as the perigynium in fruit (the green sides of perigynia are visible around the edges of the darker scales); black (purplish); with margins the same colour as the body of the scale; obtuse; 1.5–2 mm long; 0.7–0.9 mm wide; glabrous. Perianth absent. Flowers unisexual. Stamens 3. Anthers 2.8–3.2 mm long. Carpels syncarpous. Styles slender, not extending beyond the beak. Stigmas per style 2. Placentation basal. Fruit surrounded by a perigynium. Perigynia fused to the apex except for a small aperture through which the style protrudes; broadly ovate; 2.2–2.8(–3.2) mm long; 1.2–1.6 mm wide; sessile; erect or ascending; golden brown, or green (blotched); membranous; surface glossy; glabrous; papillose; appearing nerveless; with 2 keels; apices beaked with a short beak. Fruit an achene. Achenes filling the perigynia; lenticular.
Chromosome information. 2n = 76 and 80. 76. - Holmen
(1952 Greenland); Jørgensen et al. (1958 Greenland); Löve and
Löve (1965a, 1981c northern Canada); Löve and Ritchie (1966 central
Canada); Krogulevich (1971 Siberia, 1976 northern Siberia); Zhukova and
Petrovsky (1971 Wrangel Island, 1977 north eastern Asia); Packer and McPherson
(1974 northern Alaska); Zhukova et al. (1977a north eastern Asia); Yurtsev and
Zhukova (1978 E Chuk); Zhukova (1980 southern Chuk); Petrovsky and Zhukova (1981
Wrangel Island); Dalgaard (1989 western Greenland).
c. 80. - Johnson and
Packer (1968 northwestern Alaska ).
Distribution. Northern hemisphere distribution: circumpolar; Greenland, Canada, United States. Yukon, Northwest Territories Islands, Continental Northwest Territories, Nunavut Islands (Bathurst and Prince Patrick), Continental Nunavut, Northern Québec (Melville Peninsula). Arctic. Range in the Canadian Arctic Archipelago widespread. Common. Arctic Islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry Islands, Cornwallis, Banks, Victoria, Prince of Wales, Somerset, King William, Southampton, and Coats (as well as Prince Charles and Stefansson).
Ecology and habitat. Substrates: wet meadows (sometimes below snow
banks), hummocks (frost boils), around the margins of ponds, depressions of low
centre polygons, marshes (often extensive), along streams (on poorly drained
sandy berms; also on the sides of steep gullies), river terraces, lake shores
(plants emergent, or in moist areas), tundra, seashores (in coastal flats, beach
ridges and swales, and by the mouths of streams); aquatic, or imperfectly
drained moist areas, or on seepage slopes; calcareous, or halophytic; rocks
(carbonate plates, cobble, or bare bedrock), gravel, sand, silt, clay, till (or
various combinations of the above); peat (with Sphagnum), or with low
organic content (e.g., on bare wet sand), or with high organic content.
Habitats: Often locally dominant in mixed Carex and Eriophorum
meadows, often grazed by musk oxen; also found with low Salix shrubs,
Arctophila fulva, Dupontia fisheri, and occasionally
Sphagnum. These meadows are often grazed by musk oxen. When it grows near
the coast, it is usually found in freshwater wetlands (Gadallah and Jefferies,
1995). Although most often a plant of moist places, C. aquatilis var.
stans can occasionally be found in dry slopes and plains.
From a
broader geologic perspective, this species is found on silty till plains, and
alluvial outwash. It has been reported on the sides of drumlins and on colluvium
slopes at the bases of cliffs.
Notes. The division into aquatilis and stans seems to be
made differently in different areas. Inorthern Norway and Greenland, and partly
in North America, 'stans' is considered fairly narrowly whereas some
Russian floras (e.g. Fl. Murm. Obl.) consider it much more widely. This results
in discrepancies at national borders. If subsp. stans is raised to
species, the name C. concolor R.Br. has priority. (Egorova, personal
communication 2002).
Cayouette and Morisset (1985), Canad. J. Bot. 63:
1957–1982. found regular meiosis and high pollen fertility in C.
aquatilis.
The role of C. aquatilis subsp. stans in
methane efflux from boreal peatlands was studied by Pullman et al. (1995).
In a study of scale-dependent correlation's of Arctic vegetation and snow
cover in south-eastern Victoria Island, Schaefer and Messier (1995) found that
C. aquatilis subsp. stans exhibited positive associations with
various measures of snow cover. It is thought that snow cover may reduce the
rate of desiccation, protect plants from abrasion, and insulate from low
temperatures.
Carex aquatilis is a forage species for lesser snow
geese (Anser caerulescens). In their study of the nutrient contents of
principal forage plants utilized by the geese at La Perouse Bay, Manitoba,
Gadallah and Jefferies (1995) show that nutrient content in C. aquatilis
is lower than that of C. subspathacea which inhabits salt marshes nearer
to the coast. Although the lesser snow goose prefers to forage on C.
subspathacea, it will feed on the leaf tips of C. aquatilis during
the summer and on the shoot bases and rhizomes in spring and autumn.
Carex aquatilis was found to be an early colonizer of oil spills in
Alaska (Kershaw and Kershaw 1986).
Ovenden (1986) found Carex
aquatilis was an early colonizing species on the lake bed of Illisarvik, the
site of a thermokarst lake that was artificially drained in August 1978. By
1985, the lake bed was dry in most areas and wind erosion was extensive. The
surface material was either sandy peat or organic lake mud, except along the
eastern margin, where it was sandy. Substrate type appeared to have had little
influence on distributional patterns of the colonizing vegetation. More
important factors were probably erosion, surface wetness, and proximity of the
lake-bed margin. Other widespread species included Senecio congestus
Descurainia sophioides, Tripleurospermum maritimum
(Matricaria ambigua), Artemisia tilesii, Arctophila fulva,
and Stellaria longipes. Senecio and Arctophila formed dense
stands around the two small residual ponds. Eroded surfaces have a very scant
cover of Descurainia seedlings and Puccinellia tussocks. Many
elements of Illisarvik's flora are common to other recently disturbed sites near
the Arctic coast of northwestern North America.
Illustrations. • Plants in habitat. Plants dominant over a small area of a calcareous gravel and silt, seasonally wet meadow. Nunavut, Ellesmere Island, Scoresby Bay. Aiken 98–010, CAN. Photograph by Mollie MacCormac. • Close-up of plant. Plants about ten cm. high with flowering spikes at anthesis. Nunavut, Ellesmere Island, Scoresby Bay. S.G. Aiken 98–010, CAN. Photograph by Mollie MacCormac. • Close-up of plants. Plants growing on silt near a pond. Leaf associated with the inflorescence extending beyond it. Terminal spike male, at anthesis. Lower spikes female. Sachs Harbour, Banks Island, N.W.T., July 24, 1981, J.M. Gillett 18792, CAN. • Close-up of inflorescence. Terminal spike with prominent anthers. Base of the spike showing perigynia each with two stigmas. Nunavut, Ellesmere Island, Scoresby Bay. Aiken 98–010, CAN. Photograph by Mollie MacCormac. • Developing inflorescence. Small plant less than 10 cm high, growing on the edge of an Eriophorum angustifolium meadow. Developing inflorescences with the stigmas appearing fully extended and pre-anthesis anthers. N.W.T., Banks Island, Aulavik National Park, 11 July, 1999. Susan Aiken 99–046, CAN. • Close-up of developing inflorescence. Small plant growing on the edge of an Eriophorum angustifolium meadow. Developing inflorescences with the stigmas appearing fully extended and pre-anthesis anthers. N.W.T., Banks Island, Aulavik National Park, 11 July, 1999. Aiken 99–046, CAN. • Close-up of inflorescence. Terminal spike with prominent anthers. Nunavut, Ellesmere Island, Scoresby Bay. Aiken 98–010, CAN. Photograph by Mollie MacCormac. • Arctic Island distribution. • Type specimen of hybrid. Holotype of hybrid Carex x stansalina E. Lepage, C. aquatilis x C. subspathacea. Nat. Can. 83:150.1956. Nunavut, Southampton Island. H.B.Co. Post, South Bay, Aug. 25, 1934, Nicholas Polunin s.n. CAN 25083.
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).
