Vascular Plants of North Carolina
Account for Blunt Broom Sedge - Carex tribuloides   Wahlenberg
Members of Cyperaceae:
Members of Carex with account distribution info or public map:
Google Images
Section 5 » Order Cyperales » Family Cyperaceae
DistributionMore-or-less throughout the state, but least numerous in the Mountains and outer Coastal Plain.

N.B. to MN and NE, south to central FL, southeastern LA, and MO.
AbundanceFrequent to common over most of the state. Infrequent in the Mountains, and rare to uncommon in the lower Coastal Plain. Individual populations often have abundant non-flowering leafy shoots, along with fertile stems.
HabitatFloodplain forests and bottomlands of brownwater rivers; much scarcer in blackwater systems. At times in marshes.
PhenologyFlowering and fruiting May-June.
IdentificationAlthough Blunt Broom Sedge is within the difficult section Ovales, this species tends to stand out, due to the presence of abundant vegetative shoots (leaves only) adjacent to the flowering stems. Thus, the species tends to form patches of leaves with scattered fertile stems. The 6-10 (-15) spikes are bunched together at the top of the stem and are brownish green, ovoid in shape.
Taxonomic CommentsCarex tribuloides var. sangamonensis has been collected in Caswell, Durham, Hyde, and Wilson counties. This distribution makes no biogeographical sense for a Midwestern taxon, and it is likely that they represent introductions. We treat var. sangamonensis as an alien.

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 RankS4 [S5]
Global RankG5
State Status
US Status
USACE-agcpFACW link
USACE-empFACW link
County Map - click on a county to view source of record.
Photo Gallery
B.A. SorriePiedmont, irregularly inundated margin of creek off Wadsworth Rd, May 2015. MoorePhoto_natural
Select a source
Select an occurrence type