Vascular Plants of North Carolina
Account for Green Flatsedge - Cyperus virens   Michaux
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Section 5 » Order Cyperales » Family Cyperaceae
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AuthorMichaux
DistributionMostly the outer Coastal Plain; two records from the lowermost Piedmont (Richmond and Wake counties).

Mostly Coastal Plain, NC to FL and TX.
AbundanceRare; the NCNHP database lists only 9 records. Although RAB (1968) cites Carteret County only, Green Flatsedge has recently been collected or verified in 6 other counties. This is a State Special Concern species, and owing to its somewhat wide range and number of records, the website editors suggest a State Rank of S1S2 instead of just S1.
HabitatMargins of marshy beaver ponds, margins of peatland pocosins, peaty roadsides.
PhenologyFlowering and fruiting June-October.
IdentificationThis species is generally 1-2 feet tall, with a branched inflorescence and several leaflike bracts. Spikes are generally rounded in outline, composed of many spikelets; the female scales form a rough edge to each spikelet. It is very similar to C. pseudovegatus, but it has more florets (scales, seeds) per spikelet (10-40 or more vs. 10-16 in that species). It is also very similar to C. surinamensis, but the stems are scabrid on the angles (vs. smooth in that species).
Taxonomic CommentsNone

The genus Cyperus is mostly tropical and warm-temperate in distribution; thus, in NC it is much commoner in the Coastal Plain than in the Mountains and Piedmont. Most species have 1-few flowering stems (culms) from grasslike basal leaves, plus a few stem leaves. At the summit is an inflorescence of very open and branched, or tightly packed, spikes, varying among species from brown to golden brown to straw-color to reddish. The arrangement of the spikelets is important, whether like a hand (digitate) or in paired rows (pinnate); as is the shape of the achene (seed), whether bi-convex in cross-section or triangular. As a group, Cyperus tends to be weedy and readily enters disturbed ground; this is true for many natives as well as all the aliens. In recent years, following DNA research, the genus has incorporated several genera that in RAB (1968) or other manuals were separate: Hemicarpha, Lipocarpha, and Kyllinga.
Other Common Name(s)None
State RankS1 [S1S2]
Global RankG5
State StatusSC-V
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