Eriophorum L.
Cotton grass.
Cyperaceae, sedge family.
Plants caespitose, or not caespitose (with single unbranched culms); tussock forming bog or marsh plants; less than 15 cm high, or more than 15 cm high; 7–30(–80) cm high. Roots colourless, or pallid-brown, or black. Ground-level or under-ground stems horizontal, or not developed horizontally or vertically underground; rhizomatous, or stoloniferous; elongate. Scales present, or absent. Aerial stems erect; triangular in cross-section, or circular or oval in cross-section; glabrous. Leaves mostly basal, or distributed along the stems; deciduous. Petioles absent. Sheaths persisting; forming a conspicuous build up at the base of the plant, or not forming a conspicuous build up at the base of the plant; greyish brown, or brown, or reddish; with the margins fused to the apex; glabrous; collars collars absent. Ligules present; 0.3–1 mm long; membranous, or a fringed membrane (occasionally, seen at 40X); glabrous; ovate-oblong, or transversely oblong; apices acute, or obtuse; entire. Blades 30–300 mm long; 0.5–5 mm wide; appressed to the stem, or spreading from the vertical; straight; linear; triangular in cross section, or flat, or folded, or caniculate; with parallel veins; midvein conspicuously larger than the lateral veins, or midvein similar in size to other veins in the leaf; adaxial surface glabrous, or scabrous. Blades abaxial surface glabrous, or scabrous. Leaf margins entire; glabrous. Leaf apices acuminate.
Flowering stems conspicuously taller than the leaves; with leaves, or without leaves (in the upper half); uppermost leaf arising below the middle of the stem, or arising above the middle of the stem; glabrous. Flowering culm nodes not exposed. Leaf or reduced bract closely associated with the base of the inflorescence present; conspicuous and leaf-like, or reduced, or scale-like; shorter than the apex of the inflorescence; 4–50 mm long; sheathless; persistent. Inflorescences spicate; inflorescence dense; inflorescence 1–12 cm long; inflorescence 10–60 mm wide. Pedicels glabrous, or scabrous. Inflorescence a single spike, or multispicate; 1–5 spikes; lateral spikes borne on pedicels (if applicable). Individual spike(s) erect, or pendent. Bisexual spike(s) with empty bracts at the base, or without empty bracts at the base. Terminal spike with both sexes in each floret. Flowers small, less than 5 mm in diameter or length; sessile or subsessile. Floral scales black, or pale grey; with margins the same colour as the body of the scale, or with margins, and sometimes midvein paler in colour than the adjacent area of the scale; reflexed, or not reflexed (usually); acute; 4–15 mm long; 1–5 mm wide; glabrous. Perianth represented by bristles; bristles silky white, or translucent, or dull white or yellowish. Stamens 3. Anthers 0.5–5 mm long. Carpels syncarpous. Styles 3. Stigmas per style 3. Placentation basal. Fruit not surrounded by a perigynium; surrounded by perianth persisting as bristles; an achene; 1.1–3.5 mm long; black, or brown, or golden brown; glabrous. Achenes trigonous.
Chromosome information. 2n = 58, 60.
Distribution. Circumpolar, or amphi-Atlantic, or North American. Arctic, or high arctic, or low arctic. Range in the Canadian Arctic Archipelago widespread, or limited. Common, or rare.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L.Consaul, R.L. Boles, R. Elven and M.E. LeBlanc. 2001 onwards. Flora of the Canadian Arctic Archipelago. Volume 1. Pteridophytes and Monocotyledons: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 16th March 2001. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993, 1995, 2000), and Aiken, Dallwitz et al. (1999) should also be cited (see References).