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Aquatic and Wetland Vascular Plants of the Northern Great Plains

Eriophorum L. -- Cottonsedge


Solitary or sparsely tufted, grasslike, rhizomatous perennials; culms rather stout, terete to weakly trigonous, mostly solid. Leaves mostly basal, sheathing the stems; blades elongate, grasslike, flat or folded or subterete and sometimes channeled on the upper surface. Involucral bracts few, foliaceous in spp. having few to several spikelets in the inflorescence, or resembling enlarged, sterile basal scales in those with a single terminal spikelet. Inflorescence terminal, containing few to several spikelets in an umbelliform cyme, or comprised of a solitary spikelet; spikelets having a cotton tuft appearance at maturity due to the elongate, silky perianth bristles; scales many, spirally arranged, scarious. Flowers perfect; perianth of numerous, long, persistent, white to rufous bristles, greatly surpassing the scales at maturity; stamens 3; styles trifid. Achenes brown, unequally trigonous, sometimes with a short style beak.

Reference:  

Fernald, M. L.  1905.  The North American species of Eriophorum.  
     Rhodora 7:81-92, 129-136.

Lead Characteristic Go To
1 Inflorescence a single terminal spikelet; foliaceous involucral bracts absent. E. chamissonis
1 Inflorescence of few to several spikelets; foliaceous involucral bracts present. Lead 2
2 Involucral bract 1, shorter than the inflorescence. E. gracile
2 Involucral bracts 2 or 3, the longest usually surpassing the inflorescence. Lead 3
3 Midvein of the scale fading before reaching the very thin tip of the scale. E. polystachion
3 Midvein of the scale broadening toward the tip of the scale and reaching the tip. E.viridicarinatum


62. Cyperaceae, the Sedge Family
6. Eriophorum L. -- Cottonsedge
1. Eriophorum chamissonis C. A. Mey. -- Chamisso cottonsedge
2. Eriophorum gracile Koch -- Slender cottonsedge
3. Eriophorum polystachion L. -- Narrowleaf cottonsedge
4. Eriophorum viridicarinatum (Engelm.) Fern.


Return to Family -- Cyperaceae - The Sedge Family
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