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- Carex sparganioides
Carex sparganioides — bur-reed sedge
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Facts
Bur-reed sedge is found in rich, moist deciduous forests. Its spikes are relatively scattered along the inflorescence for up to 10 cm.
Habitat
Anthropogenic (human-disturbed or -maintained habitats), 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.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
- terrestrial
- New England state
- 
                                
                                    - Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
 
- stem leaf blade width
- 5–10 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
- 3.3–4.3 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
- 30–100 mm
 - Length of scale
- the scale is shorter than the perigynium
 - Lowest spike length
- 30–150 mm
 - Lowest spike stalk length
- 0 mm
 - Lowest spike width
- 8–12 mm
 - Perigynium beak
- the perigynium has a beak
 - Perigynium beak length
- 0.8–1.2 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
- 0.2–0.4 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
- 3.3–4.3 mm
 - Perigynium nerve number
- At least 0
 - Perigynium nerve texture
- 
                                
                                    - NA
- the nerves on the perigynium are raised, even after drying the perigynium
 
 - Perigynium nerves lower side
- At least 0
 - Perigynium nerves upper side
- At least 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 lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- 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)
- the carpellate scale has an awn on it
 
 - Scale awn texture
- 
                                
                                    - NA
- the carpellate scale awn does not have teeth (it may or may not have hairs)
 
 - Scale color
- white or translucent
 - Scale length
- 1.8–2.5 mm
 - Scale tip
- 
                                
                                    - the carpellate scale tip is acuminate (tapered to a narrow point)
- 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
- 1.7–2.2 mm
 - Achene width
- 1.5–1.8 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 no dots on 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
- 3–8 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
- 5–10 mm
 - Lowest leaf sheath texture
- the leaf sheath feels smooth (it may have soft hairs)
 - stem leaf blade width
- 5–10 mm
 
- 
                        Place- Habitat
- terrestrial
 - New England state
- 
                                
                                    - Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
 
 - Specific habitat
- 
                                
                                    - forests
- human-disturbed or -maintained habitats
 
 
- 
                        Stem, shoot, branch- Plant height
- 30–100 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
- At least 20 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
- present
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Maine
- extremely rare (S-rank: S1), endangered (code: E)
- Massachusetts
- uncommon to fairly widespread (S-rank: S3S4)
- New Hampshire
- extremely rare (S-rank: S1), endangered (code: E)
- Rhode Island
- historical (S-rank: SH), state historical (code: SH)
- Vermont
- fairly widespread (S-rank: S4)
From Flora Novae Angliae dichotomous key
152. Carex sparganioides Muhl. ex Willd. N
bur-reed sedge. CT, MA, ME, NH, RI, VT. Rich, mesic, often rocky, deciduous forests, shaded ditches.
Native to North America?
Yes
Sometimes confused with
- Carex cephaloidea:
- inflorescence 2-4 cm long, with crowded lower spikes, and body of perigynium with a very narrow wing up to 0.1 mm wide (vs. C. sparganioides, with the inflorescence mostly 4-10 cm long, with remote lower spikes, and body of perigynium with a narrow wing 0.1-0.2 mm wide).
![Inflorescence: Carex sparganioides. ~ By Arthur Haines. ~ Copyright © 2025 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-239x239/Cyperaceae/carex-sparganioides-in-ahaines-a.jpg) 
                         
                        ![Leaves: Carex sparganioides. ~ By Arthur Haines. ~ Copyright © 2025 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-239x239/Cyperaceae/carex-sparganioides-le-ahaines-b.jpg) 
                         
                         
                         
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