Eriophorum brachyantherum Trautv. & C.A. Meyer
In Middendorff, Reise Nord. Ost. Sibir. 1(2) 3: 98, 1856.
Eriophorum opacum (Bjornstr.) Fern.
Eriophorum vaginatum var. opacum Bjornstr.
Plants caespitose (smaller and less compact than E. vaginatum). Plants more than 15 cm high; 15–30(–45) cm high. Roots pallid-brown. Ground level or underground stems not developed horizontally or vertically. Scales present. Aerial stems erect; not filiform (0.6–1.0 mm in diameter); triangular in cross section (in the upper half), or circular or oval in cross section (in the lower half); glabrous. Leaves mostly basal. Sheaths forming a conspicuous build up at the base of the plant; brown (pallid); with the margins fused to the apex; glabrous. Ligules present; 0.5–1 mm long; transversely oblong; apices obtuse; entire. Blades straight; linear; triangular in cross section; glabrous (or minutely scaberulous seen at 40X).
Flowering stems conspicuously taller than the leaves; with leaves; uppermost leaf arising above the middle of the stem; glabrous. Leaf or reduced bract closely associated with the base of the inflorescence absent. Inflorescence spicate; dense; ovate (broadly); 1–2 cm long; 10–25(–40) mm wide; a single spike. Individual spike(s) erect. Bisexual spike(s) with empty bracts at the base (the lowest larger, opaque and 3-veined, 0.6–1 cm long). Terminal spike with both sexes in each floret. Flowers sessile or subsessile. Floral scales black; with margins the same colour as the body of the scale; not reflexed (distinguishes this taxon from E. vaginatum s.l.); acute; 6–10 mm long; 1.5–4 mm wide; glabrous. Perianth represented by bristles; bristles dull white or yellowish (often brown tinged, about 20 mm long). Anthers 1–1.5(–2) mm long (narrowly elliptical). Stigmas per style 3. Fruit 1.8–2.2 mm long; brown. Achenes trigonous.
Chromosome information. 2n = 58.
Distribution. Circumpolar. Low arctic. Range in the Canadian Arctic Archipelago limited. Rare. Arctic Islands: Baffin (Clyde Inlet), Southampton (Coral Harbour).
Ecology and habitat. Substrate wet meadows, river terraces, tundra; imperfectly drained; calcareous; rock, silt; with high organic content, or peat. A muskeg species that rarely extends far beyond tree line.
Illustrations. • 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).
