Carex retrorsa Schwein. - Retrorse Sedge


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Carex retrorsa - (image 1 of 4)



Family: Cyperaceae


Section Vesicariae


Swamps, shores, wet thickets, sedge meadows.




Newfoundland to Saskatchewan, south to PA, OH, MI, WI, and MN; also occurs in Eurasia.


Perennial from a very short or inconspicuous rhizome; stems stout, densely clustered, 30-100 cm, smooth distally; basal sheaths dark reddish brown; ligules longer than wide; leaves and especially the sheaths septate-nodulose; main leaves mostly 4-10 mm wide; leaves subtending the pistillate spikes sheathless or only shortly sheathing, at least the lowest one several times longer than the inflorescence; spikes several, crowded, sessile or nearly so, or the lowest one more remote and on a slender peduncle; lower spikes pistillate, the upper staminate or androgynous; pistillate spikes 1.5-5 cm long and 1.5-2 cm thick; pistillate scales conspicuous, shorter and narrower than the perigynia; perigynia numerous, densely crowded in 8 or more rows, widely spreading above and the lowest ones often reflexed, glabrous, shining, distinctly 6-13-nerved, 7-10 mm long, firm but somewhat inflated, ellipsoid to subglobose and often somewhat oblique, narrowed to a prominent, slender, smooth beak 2-4 mm long with short, straight teeth 0.3-1.1 mm long; achene brown, narrowly trigonous, 2 mm, smooth, loose in the lower part of the perigynium, the style persistent, bony, becoming contorted as it matures.


Fruiting June to August

Wetland indicator: OBL

The name refers to the reflexed perigynia on the lower portion of the spike. These plants were found growing on a deep marl substrate so this species is apparently tolerant of very high pH. A robust plant that may rarely form hybrids with C. lupulina or C. lupuliformis with intermediate morphology.


Ball, P.W. and A.A. Reznicek. 2002. Carex, In: Flora of North America Editorial Committee, Eds. Flora of North America North of Mexico. Volume 23. Oxford University Press, New York.


Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY




Michael Hough 2018