Kobresia myosuroides (Vill.) Fiori
Cyperaceae, sedge family.
In Fiori & Paol., Fl. Italiana 1: 125 1896.
Carex myosuroides Vill., Prosp. Hist. Pl. Dauphiné 17. 1779.
Kobresia bellardii (All.) Degl. ex Loisel., Fl. Gall. 2: 626. 1807.
Carex bellardii All. 1785
Vegetative morphology. Plants perennial herbs; (5–)10–20(–35) cm high; caespitose (very tightly); with densely packed old fibrillose sheaths at the base and somewhat flexuous leaves; very similar in general appearance to Carex nardina with culms not much longer than the leaves. Roots pallid-brown, or black. Ground-level or under-ground stems not developed horizontally or vertically. Scales absent. Aerial stems erect; not conspicuously jointed; filiform (wiry, 0.4–0.6 mm in diameter); circular or oval in cross-section; glabrous. Leaves in a basal tuft; alternate. Petioles absent. Sheaths persisting; forming a conspicuous build up at the base of the plant (similar to Carex nardina); greyish brown, or reddish (pale orange, somewhat glossy, bladeless); collars absent (closed, somewhat glossy). Ligules present; 0.1–0.2 mm long. Blades 20–150(–200) mm long; 0.2–0.7 mm wide (filiform). Blades straight; linear; circular in cross section, or caniculate (without a pronounced midrib); veins parallel. Blades adaxial surface glabrous (sometimes scabrous along the margins, or even with sparse cilia that are not much shorter than those in Carex nardina). Blades abaxial surface glabrous. Blade margins scabrous (scaberulous or not seen on inrolled margins).
Reproductive morphology. Plants monoecious. Flowering stems present. Flowering stems about as high as the leaves (or slightly taller); with leaves, or without leaves; hairy. Leaf or reduced bract closely associated with the base of the inflorescence absent. Inflorescence spicate; linear; 1–3 cm long; 2–4(–5) mm wide; a single spike (in appearance; made up of 10–20 tiny spike-like panicles "spikelets"; with one male flower above and one female flower below). Individual spike(s) erect. Terminal spike staminate at the apex (lateral "spikelets" have male flowers above and female flowers below). Staminate flowers inconspicuous (each subtended by a staminate scale). Floral scales orange brown; with margins, and sometimes midvein paler in colour than the adjacent area of the scale (mid-vein distinct almost to the tip); lanceolate; 2–3.5(–4.5) mm long; 1.5–2 mm wide; glabrous (apex obtuse or cuspidate). Perianth absent. Stamens 3. Anthers 1.5–2 mm long. Carpels syncarpous. Stipes 3 mm long. Styles 1; long and thick (black, and longer than the floral scales). Placentation basal. Fruit surrounded by a perigynium. Perigynia open on one side; broadly ovate; 2–3.5 mm long; 1–1.2 mm wide; sessile; erect or ascending; brown; membranous; surface dull; glabrous; appearing nerveless; apices without a beak. Fruit an achene (elliptical). Fruit 0.8–1.2 mm long; golden brown. Achenes not filling the upper part of the perigynia; trigonous (loosely so, sometimes becoming black balls of fungus infection).
Chromosome information. 2n = 52-58-66.
52-58-66. - Böcher (1938a, 1938c Greenland, 2n = 52);
Heilborn (1939, 2n = 52–59); Holmen (1952 Greenland, 2&#;n&#;none =
60–66); Jørgensen et al. Löve and Löve (1956b Iceland,
2n = 60); (1958 Greenland, 2n = 52–56); Johnson and Packer
(1968 northwestern Alaska , 2n = 58); Engelskjøn and Knaben (1971
southern and northern Norway, 2n = 58); Zhukova and Petrovsky (1976 W
Chuk, 2n = 58); Löve and Löve (1981c northern Canada, 2n
= 58); Zhukova (1982 north eastern Asia, 2n = 58); Stoeva and Popova
(1988 SE Europe, 2n = 58); Hoshino et al. (1993a China, 2n = 56).
A chromosome report of 2n = c.36 from southern Siberia (Krogulevich
1971) is omitted until a voucher can be studied. Otherwise this is a nearly
perfect example of the approach of the Löves and many other counters of
chromosomes. Before 1968 several different and 'diffuse' chromosome numbers are
reported, but never exactly 2n = 58. From Johnson and Packer (1968) and
onwards every chromosome counter has found 2n = 58 as the exact number,
with the exception of some Japanese who did not know what they were expected to
find. And Löve and Löve (1975) have only listed the exact 2n =
58 counts and omitted all the others, including every single count from
Greenland and their own previous count from Iceland. There is really no
convincing evidence that there is one and only one chromosome number in this
species, just some indications that there is a predominant one! (Elven).
Distribution. Northern hemisphere distribution: circumpolar; Greenland, Canada. Yukon, Northwest Territories Islands, Continental Northwest Territories, Nunavut Islands, Continental Nunavut, Northern Québec. Arctic. Range in the Canadian Arctic Archipelago widespread. Common. Arctic Islands: Baffin and Devon (voucher HbO), Ellesmere, Axel Heiberg, and Parry Islands (Melville), Banks, Victoria, Somerset, and Southampton.
Ecology and habitat. Substrates: hummocks; imperfectly drained moist areas (rarely), or on solifluction slopes, or dry (usually); calcareous; rocks, gravel, sand, clay; with low organic content, or with high organic content (less commonly). Habitats: Typically found in dry, sparsely vegetated places, often on exposed slopes with Saxifraga, Dryas, or Salix. Occasionally reported in moister areas in wet swales near beaches.
Notes. In the vegetative state this species can be a challenge to
distinguished from Carex nardina. Polunin (1940) noted that except for
local variations in luxuriance, this plant appear to be much the same in the
eastern Canadian Arctic Archipelago. He predicted that in time it may prove to
be almost complete on ice-free land, although it had not been recorded from
several considerable areas. He also observed that it is "remarkably overlooked"
and for this reason possibly under collected.
Kobresia myosuroides is
reported to proliferate in "single passage" vehicle tracks through high arctic
tundra, Lake Hazen, Ellesmere Island. Vehicle tracks tend to be depleted of
nutrients and generally low in vegetative cover (Kevan et al., 1995).
The
roots of K. myosuroides have been shown to have the ability to absorb
free amino acids as well as inorganic nitrogen (Raab et al., 1996). Such an
adaptation is highly advantageous in the Arctic where inorganic nitrogen is
often limiting.
Illustrations. • Herbarium specimen. Two densely tufted plants approximately 15 cm high. Note the build-up of orange-brown sheaths at the base and the linear inflorescences. CAN 273552. • Close-up of inflorescence. Close-up of narrow spicate inflorescence from previous image. • Arctic Island distribution.
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).
