Vascular Plants of North Carolina
Account for Fibrous-root Sedge - Carex communis   L.H. Bailey
Members of Cyperaceae:
Members of Carex with account distribution info or public map:
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Section 5 » Order Cyperales » Family Cyperaceae
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AuthorL.H. Bailey
DistributionMountains and western Piedmont.

Southern Labrador to MN south to NC and AR.
AbundanceFrequent to common in the Mountains; uncommon in the western and northwestern Piedmont.
HabitatDry hardwoods (often oak-hickory) and mixed pine-hardwoods, forest openings, bluffs. At moderate elevations, often in ravines and on other steep slopes.
PhenologyFlowering and fruiting May-June.
IdentificationPlants are densely cespitose, rhizomes short or absent, as opposed to those in C. pensylvanica and C. lucorum; perigynia bodies are globose to obovoid (vs. ellipsoid in C. albicans, C. nigromarginata, and C. floridana). Flowering stems (culms) tend to be lax/lazy and grow parallel to the ground.
Taxonomic CommentsSee also C. amplisquama and that species account for details. Derick Poindexter of UNC Chapel Hill has been studying the Acrocystis group, and we can expect some major changes in the taxonomy.

The genus Carex is the largest in North America, and among the largest in the world. In temperate and boreal regions, Carex is often the dominant or co-dominant ground layer in many habitats. Seeds (achenes) are valuable food for birds and small mammals, while foliage is used by birds and mammals to make nests and as food by mammals. Species of Carex often look vastly different from one another -- spikes erect vs. drooping, tiny inflorescence vs. whopping, culms leafy vs. naked, perigynia beaked vs. beakless, stems densely bunched vs. single, etc. The genus has been divided into many sections (or groups), based on shared characters; some taxonomists have suggested that these be different genera, but that proves unworkable (so far). All Carex share the feature of a perigynium (an outer covering) which completely surrounds the achene (seed). This covering may fit tightly or loosely (like a small bladder), depending on which group or species. Details of perigynia shape, ornamentation, presence and size of beak, number of striations (or veins) are all important ID features. In recent years Rob Naczi and colleagues have stressed the importance of arrangement of perigynia -- whether spiral (3+ ranks) or distichous (2-ranked) -- and have named a number of new species as well as split off some older synonyms. Therefore, RAB's (1968) key, excellent for its time, can only be used in a general way today. Members of some sections of Carex are difficult to key out (notably Ovales, Laxiflorae, Griseae); this is in part due to variation among individuals of a species, or failings of the key. FNA has drawings of most species and some species may be found in two or more places within a key, to acount for variability. New species to NC, and new to science(!), continue to be found in NC.
Other Common Name(s)None
State RankS3? [S4]
Global RankG5
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