Vascular Plants of North Carolina
Account for Southeastern Flatsedge - Cyperus filiculmis   Vahl
Members of Cyperaceae:
Members of Cyperus with account distribution info or public map:
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Section 5 » Family Cyperaceae
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AuthorVahl
DistributionCoastal Plain and lowermost southern Piedmont. Occurs on Roanoke Island, but not on the Outer Banks. Gaps in the map likely will be filled over time.

Coastal Plain, DE to FL and TX.
AbundanceGenerally frequent in the southern Coastal Plain and Sandhills, but uncommon to infrequent farther northward. It is typically widely scattered within good habitat, usually only a few plants at any one place.
HabitatDry to xeric open sandy soil of pinelands, pine-oak barrens, Carolina bay rims, disturbed areas.
PhenologyFlowering and fruiting July-October.
IdentificationVery distinct in its single (sometimes 2-3) dense head atop the solitary stem. It is close to C. lupulinus, but differing in longer anthers (0.8-1.0 mm long vs. 0.3-0.6 mm long).
Taxonomic CommentsA synonym is C. martindalei Britton.

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)There are very few references giving common names for this species; this website uses Weakley's (2018) common name.
State RankS4
Global RankG5
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