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Carex cephaloidea — thin-leaved sedge
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Facts
Thin-leaved sedge is similar to several other sedges, but has very short carpellate scales half the length of the perigynia, and with a relatively congested inflorescence of 5-10 spikes.
Habitat
Floodplain (river or stream floodplains), forests
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
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Characteristics
- Habitat
 - 
                                
                                    
- terrestrial
 - wetlands
 
 
- New England state
 - 
                                
                                    
- Connecticut
 - Maine
 - Massachusetts
 - New Hampshire
 - Vermont
 
 
- stem leaf blade width
 - 4–8 mm
 
- Lowest bract sheath
 - the lowest bract has no sheath (or a very short sheath up to four millimeters in length)
 
- Spike on stalk
 - the lowest spike on the plant is not borne on a peduncle
 
- Top spike
 - the uppermost spike contains both staminate and carpellate flowers, with the carpellate flowers located below, or intermixed with, the staminate flowers
 
- Perigynium hairs
 - the perigynium has no hairs
 
- Perigynium length
 - 3–4.5 mm
 
- Leaf sheath color
 - the leaf sheath has no pink, red or purple tinting
 
- Leaf blade texture
 - the leaf blade is smooth and hairless, or rough and sandpapery
 
- Perigynium beak teeth
 - the perigynium beak is divided at the top into two teeth
 
- 
                        
Flowers
- Anther length
 - 0.7–1.3 mm
 
- Bumps on fruit
 - there are no papillae on the perigynium surface
 
- Inflorescence length
 - 20–40 mm
 
- Length of scale
 - the scale is shorter than the perigynium
 
- Lowest spike length
 - 15–40 mm
 
- Lowest spike stalk length
 - 0 mm
 
- Lowest spike width
 - 8–10 mm
 
- Perigynium beak
 - the perigynium has a beak
 
- Perigynium beak length
 - 1–1.3 mm
 
- Perigynium beak orientation
 - the beak of the perigynium is straight, and in line with the perigynium
 
- Perigynium beak serrations
 - the perigynium beak has tiny serrations along the edges
 
- Perigynium beak teeth
 - the perigynium beak is divided at the top into two teeth
 
- Perigynium beak teeth length
 - 0.2–0.5 mm
 
- Perigynium color
 - green
 
- Perigynium cross-section
 - the perigynium is planoconvex (flat on one surface and rounded on the other) in cross-section
 
- Perigynium hairs
 - the perigynium has no hairs
 
- Perigynium length
 - 3–4.5 mm
 
- Perigynium nerve number
 - 4–7
 
- Perigynium nerve texture
 - 
                                
                                    
- NA
 - the nerves on the perigynium are raised, even after drying the perigynium
 
 
- Perigynium nerves lower side
 - 4–7
 
- Perigynium nerves upper side
 - 0
 
- Perigynium orientation
 - 
                                
                                    
- the perigynia are angled outwards
 - the perigynia are oriented vertically or pressed against the axis or adjacent perigynia
 
 
- Perigynium shape
 - the perigynium body is ovate (egg-shaped)
 
- Perigynium width
 - 1.5–2.5 mm
 
- Perigynium winged
 - the perigynium has wings on it
 
- Pollen- and seed-producing spikes
 - some of the spikes produce perigynia
 
- Pollen-producing spike length
 - 0 mm
 
- Pollen-producing spike number
 - 0
 
- Pollen-producing spike peduncle length
 - 0 mm
 
- Pollen-producing spike width
 - 0 mm
 
- Scale awn
 - The carpellate scale does not have an awn (it may have a short point)
 
- Scale awn texture
 - NA
 
- Scale color
 - 
                                
                                    
- tan
 - white or translucent
 
 
- Scale length
 - 1.5–2 mm
 
- Scale tip
 - 
                                
                                    
- the carpellate scale tip is acute (has a sharp point)
 - the carpellate scale tip is obtuse (has a blunt point)
 
 
- Spike on stalk
 - the lowest spike on the plant is not borne on a peduncle
 
- Spike orientation
 - the spikes are oriented vertically or pressed against the axis
 
- Spikes per stem
 - 2-15
 
- Stigma branching
 - the stigmas have two branches
 
- Top spike
 - the uppermost spike contains both staminate and carpellate flowers, with the carpellate flowers located below, or intermixed with, the staminate flowers
 
 - 
                        
Fruits or seeds
- Achene dimples
 - the achene has no folds or dimples
 
- Achene length
 - 1.6–2 mm
 
- Achene width
 - 1.3–1.7 mm
 
- Style persistence
 - the style falls off the mature achenes
 
 - 
                        
Growth form
- Rhizomes
 - there are no rhizomes, or the rhizomes are very short
 
 - 
                        
Leaves
- Leaf arrangement
 - the leaves are all produced from the base of the plant
 
- Leaf blade cross-section
 - The leaf blade is folded lengthwise, with one prominent midvien
 
- Leaf blade texture
 - the leaf blade is smooth and hairless, or rough and sandpapery
 
- Leaf bumps
 - the upper surface of the leaf blade does not have papillae
 
- Leaf sheath bumps
 - there are no papillae at the top edge of the leaf sheath
 
- Leaf sheath color
 - the leaf sheath has no pink, red or purple tinting
 
- Leaf sheath dots
 - there are white dots on the green tissues of the leaf sheathes
 
- Leaf sheath folds
 - the leaf sheath has corrugations on it
 
- Leaf sheath texture
 - the leaf sheath feels smooth, and has no hairs
 
- Ligule length
 - 3–7 mm
 
- Lowest bract sheath
 - the lowest bract has no sheath (or a very short sheath up to four millimeters in length)
 
- Lowest leaf blade width
 - 4–8 mm
 
- Lowest leaf sheath texture
 - the leaf sheath feels smooth (it may have soft hairs)
 
- stem leaf blade width
 - 4–8 mm
 
 - 
                        
Place
- Habitat
 - 
                                
                                    
- terrestrial
 - wetlands
 
 
- New England state
 - 
                                
                                    
- Connecticut
 - Maine
 - Massachusetts
 - New Hampshire
 - Vermont
 
 
- Specific habitat
 - 
                                
                                    
- forests
 - river or stream floodplains
 
 
 - 
                        
Stem, shoot, branch
- Plant height
 - 30–120 cm
 
- Relative stem height
 - 
                                
                                    
- the main stem is equal to or shorter than the leaves
 - the main stem is taller than the leaves
 
 
- Spike internode length
 - Up to 10 mm
 
- Stem cross-section
 - the main stem is roughly triangular in cross-section
 
- Stem spacing
 - the stems grow close together in compact clusters or tufts
 
 
Wetland status
Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)
In New England
Distribution
- Connecticut
 - present
 
- Maine
 - present
 
- Massachusetts
 - present
 
- New Hampshire
 - present
 
- Rhode Island
 - absent
 
- Vermont
 - present
 
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
 - fairly widespread (S-rank: S4)
 
- New Hampshire
 - rare (S-rank: S2), threatened (code: T)
 
From Flora Novae Angliae dichotomous key
145. Carex cephaloidea (Dewey) Dewey N
thin-leaved sedge. Carex muricata L. var. cephaloidea Dewey; C. sparganioides Muhl. ex Willd. var. cephaloidea (Dewey) Carey • CT, MA, ME, NH, VT; also reported from RI by George (1992), but specimens are unknown. Mesic, often rich, soils of upland deciduous forests and riparian forests.
Native to North America?
Yes
Sometimes confused with
- Carex sparganioides:
 - inflorescence mostly 4-10 cm long, with remote lower spikes, and body of perigynium with a narrow wing 0.1-0.2 mm wide (vs. C. cephaloidea, with the inflorescence 2-4 cm long, with crowded lower spikes, and body of perigynium with a very narrow wing up to 0.1 mm wide).
 
Synonyms
- Carex muricata L. var. cephaloidea Dewey
 - Carex sparganioides Muhl. ex Willd. var. cephaloidea (Dewey) Carey