Flora of the Canadian Arctic Archipelago
English: Sheathed cotton-grass,
French: Linaigrette à large gaine, linaigrette dense,
Cyperaceae, Sedge family.
Published in Sp. Pl. 52. 1753.
Type: Described from Europe, selected by Simpson in Jarvis et al., Regnum Veget. 127: 45–46. 1993. Holotype: UPS: Herb. Burser I: 43.
Synonymy. Eriophorum spissum Fernald, Rhodora 27: 208. 1925.
Eriophorum vaginatum L. subsp. spissum (Fernald) Hultén, Acta Univ. Lund., n. s., sect. 2, 38, 1: 286. 1942.
Vegetative morphology. Plants (10–)15–40(–60) cm high; perennial herbs; caespitose; in dense single compact tufts (forming conspicuous tussocks). Only fibrous roots present. Roots pallid-brown. Ground level or underground stems absent. Aerial stems erect; not filiform. Leaves mainly basal; alternate; marcescent (building up large round tussocks). Petioles absent. Sheaths present; persisting; forming a conspicuous build-up at the base of the plant; greyish brown, or reddish orange (or pale orange-brown); with the margins fused to the apex; glabrous; sheath collars absent. Ligules present; 0.3–1 mm long; membranous (often turning pale brown); glabrous. Ligule apices acute, or obtuse; entire. Leaves grass-like. Blades 50–150 mm long, 0.6–1(–1.2) mm wide, appressed to the stem or spreading. Leaves filiform. Blades straight, linear (filiform), flat, veins parallel, midvein similar in size to other veins in the leaf. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blade margins glabrous (usually, sometimes scaberulous towards the tip); apices acuminate.
Reproductive morphology. Flowering stems solitary. Flowering stems triangular in cross section, or circular or oval in cross section. Flowering stems conspicuously taller than the leaves; with leaves (not closely associated with the apex); uppermost leaf arising below the middle of the stem, or uppermost leaf arising above the middle of the stem (bladeless sheaths 1–3 per culm, expanding distally to 1 mm wide). Leaf or reduced bract subtending the base of the inflorescence absent. Flowers solitary (numerous flowers in a solitary inflorecence), or in inflorescences. Inflorescences spicate and head-like (a single spike); dense; oblong, or ovate, or globose or sub-globose; 1.5–2 cm long (in flower 2.0–5.5 cm in fruit); 10–35 mm wide. Pedicels absent. Inflorescence unispicate. Individual spike(s) erect. Bisexual spike(s) with empty bracts at the base (true involucral bracts absent). Terminal spike with both sexes in each floret. Involucral bracts absent. Floral scales with margins paler than body of the scale (spreading at maturity, greenish gray with white hyaline margins to 1 mm wide; empty scales more than 10, ovate-lanceolate, proximal scales reflexed or spreading at maturity, 5–10 mm long); reflexed (at maturity); ovate, or lanceolate (proximal scales reflexed or spreading at maturity); (5–)7–10(–14) mm long; 2–4 mm wide; glabrous; apex acute. Perianth represented by bristles (the "cotton" of cotton grasses) (long, 10 or more). Perianth bristles silky white, or translucent (rarely reddish to brown, 10–18 mm long). Sepals modified (but not a pappus). Stamens 3. Anthers splitting longitudinally. Anthers (1–)1.6–3 mm long. Ovary carpels 3; syncarpous. Styles 3. Stigmas per ovary 3. Placentation basal. Ovules per ovary 1. Fruit sessile; surrounded by a perianth persisting as bristles; dry; an achene; ovoid, or obovate; black, or brown (grey); (1.1–)1.9–3.5 mm long; 0.5–0.6 mm wide; glabrous (mostly dull, base cuneate, apex acute with a beak more often oblique or curved than straight, mostly cylindrical, 0.15–0.3 mm long, 0.05–0.1 wide at the base); indehiscent. Achenes trigonous (apex minutely apiculate). Seeds 1.
Chromosome information. 2n = 58.
2n = 57-58-60. Eriophorum vaginatum L. subsp. vaginatum
2n = 60. Håkansson (1928, northern Europe); Löve (1954b); Sorsa (1963b, Finland); Zhukova (1968, northeastern Asia); 2n = 57. Johnson and Packer (1968, northwestern Alaska); Zhukova and Tikhonova (1973, Chukotka); Packer and McPherson (1974, northern Alaska); Krogulevich (1976a, northern Siberia); Zhukova et al. (1977, northeastern Asia);
Eriophorum vaginatum subsp. spissum (Fernald) Hultén
Yurtsev and Zhukova (1978, eastern Chukotka); Löve (1981d, central Canada); Kozhevnikov et al. (1986, northeastern Asia). Some more southern counts.
2n = 58. Löve (1954b); Löve and Löve (1965, 1966b, northeastern USA); Löve (1981d, central Canada);
2n = about 60. Hedberg (1967; northern Canada);
2n = 61. Gervais et al. (1999, eastern Canada).
The chromosome list of Löve and Löve (1975) applied the Hultén concept of this subspecies, which means that at least four of the seven counts they listed for subsp. spissum refer to subsp. vaginatum (Johnson and Packer 1968, Alaska; Zhukova 1968, northeastern Asia; Zhukova and Tikhonova 1973, northeastern Asia; and Packer and McPherson 1974, Alaska). The count of Hedberg (1967) may also belong to subsp. vaginatum (Elven et al. 2003).
Ecology and habitat. Substrates: hummocks (with heath), around the margins of ponds, marshes (along the edges), tundra (swales, peaty soils); aquatic, imperfectly drained moist areas; with high organic content; acidic. Found in wet meadows with Carex and other Eriophorum species, usually on higher ground than other species of Eriophorum, e.g., angustifoliumor scheuchzeri that may be growing nearby in standing water.
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec. Range in the Canadian Arctic Archipelago widespread (in southern regions). Common. Arctic. Arctic islands: Baffin and Parry islands (Melville), Banks, Victoria, and Southampton.
General notes. Two races have been recognised, a widely distributed subsp. vaginatum in Eurasia and northwestern North America and a more restricted subsp. spissum in northeastern North America and Greenland. Porsild (1957) suggested that the western subsp. vaginatum gradually passes into subsp. spissum east of the 100th meridian. Elven et al. (2003) accepted this concept, which was also mapped by Porsild and Cody (1980). Hultén (1968) had a different concept where the two races were largely sympatric, both occurring in Alaska and Yukon. Specimens he annotated as subsp. spissum from Alaska (in S) are inseparable from European and type E. vaginatum s.s. Only one taxon is recognised by Ball and Wujek (2002) in Flora of North America. If two subspecies are accepted, the plants from Banks Melville and Victoria Islands belong to subsp. vaginatum, those from Baffin and Southampton to subsp. spissum.
A study of the effects of variable soil oxygen and nutrient availability of E. angustifolium and E. vaginatum was done by Gebauer et al. (1995) near Toolik Lake, Alaska. It was shown that whole-plant growth in E. vaginatum improved in flooded soils, but only when nitrogen availability was high. In areas of low nitrogen availability, growth was reduced by 20% compared to growth in drier more aerobic soil.
The roots of E. vaginatum have been shown to have the ability to absorb free amino acids as well as inorganic nitrogen (Chapin et al. 1993). This was the first documented example of a non-mycorrhizal plant with this capability. Such an adaptation is highly advantageous in the Arctic where inorganic nitrogen is often limiting. Factors regulating the uptake of ammonium and glycine in the field were investigated by Leadley et al. (1997). Nitrogen supply rate was found to be more important than soil factors (buffer capacity and diffusion coefficient), root density, or root uptake kinetics.
Leadly et al. (1997) presented a model of nitrogen uptake by Eriophorum vaginatum roots in the field and discuss some of the ecological implications.
Moorhead et al. (1993) modelled the relative contributions of phosphatases associated with the living roots of E. vaginatum and phosphatases associated with soil microbes to the phosphorus released from the substrate within the tussocks of the plant. They found that the former contributed 4% of the total phosphorus released, but that this amount was almost twice the annual demand for the plant. Thus, E. vaginatum may obtain a significant amount of phosphorus from the activity of root surface phosphatase. They also found that 28% of the phosphatase activity occurred during a brief period of time in autumn when substrate availability was high. Since maximum growth occurs early in the year, E. vaginatum must draw on reserves from the previous year to sustain growth.
McGraw (1993) studied ecological genetic variation in seed banks and reported on the differentiation of extant and seed-bank-derived populations of Eriophorum vaginatum.
The role of E. vaginatum in methane flux from boreal peat-lands was studied by Pullman et al. (1995).
Stoner et al. (1982) studied seasonal dynamics and standing crops of biomass and nutrients in a subarctic tundra vegetation in Alaska and found the total aboveground and belowground standing crop or organic matter and biomass was greater in an E. vaginatum tussock tundra than on an adjacent north-facing slope.
Illustrations. • Habitat. Two tussocks of previous season's leaves. This season's inflorescences are developing. N.W.T., Banks Island, Aulavik National Park, near Green Cabin. June 29, 1999. Aiken 99–009. CAN. Scale bar in cm. • Close-up of plant. Close-up of a plant with an accumulation of sheaths at the base and a pre-anthesis inflorescence. Nunavut, Baffin Island, Koukdjuak River, 5 miles north of Kimmirut. 25 June, 1931. J.D. Soper 125749. CAN 28392. • Close-up of plant. Close-up of a plant with an accumulation of sheaths at the base and a post-anthesis inflorescences with lead gray scales. Nunavut, Southampton Island, vicinity of Salmon Pond. 1970. G.R. Parker SP-70–158. CAN 368132. • Inflorescences. Single head inflorescence covered with conspicuously long spent anthers. N.W.T., Banks Island, Aulavik National Park, near Green Cabin. 29 June, 1999. Aiken 99–009. 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..