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- Carex cephaloidea
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
 
                         
                         
                         
                         
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