Eriophorum vaginatum L. s.l.
Sp. Pl. 52. 1753
Eriophorum vaginatum var. spissum (Fern.) Boivin
Eriophorum spissum Fern.
Eriophorum spissum var. erubescens (Fern.) Fern.
Plants caespitose. Plants less than 15 cm high, or more than 15 cm high; (10–)15–40(–80) cm high. Roots pallid-brown. Ground level or underground stems not developed horizontally or vertically. Scales absent. Aerial stems erect; not filiform; triangular in cross section, or circular or oval in cross section; glabrous. Leaves distributed along the stems; simple. Sheaths persisting; forming a conspicuous build up at the base of the plant; greyish brown, or reddish (or pale orange brown); with the margins fused to the apex; glabrous. Ligules present; 0.3–1 mm long; ovate-oblong, or transversely oblong; apices acute, or obtuse; entire. Blades straight; linear; triangular in cross section; glabrous, or scabrous.
Flowering stems conspicuously taller than the leaves; glabrous. Leaf or reduced bract closely associated with the base of the inflorescence absent. Inflorescence spicate; dense; globose or subglobose; 1.5–5.5 cm long; 10–35 mm wide; a single spike. Individual spike(s) erect. Bisexual spike(s) with empty bracts at the base. Terminal spike with both sexes in each floret. Flowers sessile or subsessile. Floral scales pale grey; with margins paler than body of scale (spreading at maturity); acute; 7–14 mm long; 2–4 mm wide; glabrous. Perianth represented by bristles; bristles silky white, or translucent. Anthers 1.6–3 mm long. Stigmas per style 3. Fruit 1.1–1.4 mm long; black, or brown (grey). Achenes trigonous.
Chromosome information. 2n = 58.
Distribution. North American. Arctic. Range in the Canadian Arctic Archipelago wide-spread. Common. Arctic Islands: Baffin and Parry Islands (Melville), Banks, Victoria, and Southampton.
Ecology and habitat. Substrate hummocks (with heath), around the margins of ponds, marshes (along the edges), tundra; aquatic, or imperfectly drained, or dry; calcareous; with high organic content. Found in wet meadows with Carex and Eriophorum. In shallow water at the edge of pools, it can be found with with Hippurus vulgaris and Ranunculus pallasii. On drier tundra, it is associated with mosses, heath, and lichens.
Notes. The role of E. vaginatum in methane flux from boreal peatlands was studied by Pullman et al. (1995).
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 availibility, 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 III et al., 1993). This is 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.
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 phosporus released, but that this amount was almost twice the annual demand for the plant. Thus, E. vaginaturm 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.
Porsild (1957) considered Eriophorum vaginatum subsp. vaginatum a western species; east of the 100th meridian it gradually passes into subsp. spissum. In FNA it is treated as subsp. vaginatum (western-northern) and subsp. spissum (eastern-southern) but there is a lot of overlap.
Illustrations. • Plant in habitat. Two tussocks of previous seasons leaves. This season's inflorescences are developing. N.W.T., Banks Island in Aulavik National Park, near green cabin, June 29, 1999. Susan Aiken 99–009, CAN. • Close-up of plant. Close-up of the plant with an accumulation of sheaths at the base and a pre-anthesis inflorescence. Collected Nunavut, Baffin Island, Koukdjuak River, 5 miles north of Lake Harbour, J.D. Soper, 125749, 25 June, 1931, CAN 28392. • Close-up of plant. Close-up of the plant with an accumulation of sheaths at the base and a post-anthesis inflorescences with lead gray scales. Collected Nunavut, Southampton Island, vicinity of Salmon Pond, 64 12 N, 85 W. G.R. Parker, SP-70–158, 1970. CAN 368132. • Inflorescences. Single head inflorescence covered with spent anthers. N.W.T., Banks Island in Aulavik National Park, near green cabin, June 29, 1999. Susan Aiken.99–009, CAN. • Arctic Island distribution.
Cite this publication as: Aiken, S.G., Boles, R.L., and Dallwitz, M.J. 1999 onwards. ‘Cyperaceae of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval.’ Version: 6th November 2000. http://http://www.mun.ca/biology/delta/arcticf/. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
