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- Carex platyphylla
Carex platyphylla — broad-leaved sedge
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Facts
As the name suggests, broad-leaved sedge does have broad leaves, but it is distinguished from other sedges with broad leaves by its glaucous (hairless), blue-green leaves. It inhabits moist forests, usually on high-pH soils.
Habitat
Forests, talus and rocky slopes
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
- 2–6 mm
- Lowest bract sheath
- the lowest bract has a sheath longer than four millimeters
- Spike on stalk
- the lowest spike on the plant has a peduncle
- Top spike
- the uppermost spike contains only staminate flowers
- Perigynium hairs
- the perigynium has no hairs
- Perigynium length
- 3–3.2 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 not divided at the tip into two teeth, or the teeth are very tiny
- 
                        Flowers- Anther length
- 3.3–4 mm
 - Bumps on fruit
- there are no papillae on the perigynium surface
 - Length of scale
- the scale is nearly as long as, or longer than, the perigynium
 - Lowest spike length
- 6–16 mm
 - Lowest spike stalk length
- 0–22 mm
 - Lowest spike width
- 2.8–3.8 mm
 - Perigynium beak
- the perigynium has a beak
 - Perigynium beak orientation
- the beak of the perigynium is curved, or angled out from the perigynium
 - Perigynium beak serrations
- the perigynium beak has no serrations
 - Perigynium beak teeth
- the perigynium beak is not divided at the tip into two teeth, or the teeth are very tiny
 - Perigynium beak teeth length
- 0 mm
 - Perigynium color
- green
 - Perigynium cross-section
- the perigynium is trigonous (triangular) in cross-section
 - Perigynium hairs
- the perigynium has no hairs
 - Perigynium length
- 3–3.2 mm
 - Perigynium nerve number
- At least 40
 - Perigynium nerve texture
- the nerves on the perigynium are raised, even after drying the perigynium
 - Perigynium nerves lower side
- At least 20
 - Perigynium nerves upper side
- At least 20
 - Perigynium orientation
- the perigynia are oriented vertically or pressed against the axis or adjacent perigynia
 - Perigynium puffy
- the achene is tightly enclosed by the perigynium
 - Perigynium shape
- the perigynium body is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
 - Perigynium width
- 1.8–2 mm
 - Perigynium winged
- the perigynium has no wings
 - Pollen- and seed-producing spikes
- some of the spikes produce perigynia
 - Pollen-producing spike length
- 6–14 mm
 - Pollen-producing spike number
- 1
 - Pollen-producing spike peduncle length
- 1–8 mm
 - Pollen-producing spike width
- 2–4 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
- 
                                
                                    - green
- white or translucent
 
 - Scale length
- 3–6 mm
 - Scale tip
- the carpellate scale tip is acute (has a sharp point)
 - Spike on stalk
- the lowest spike on the plant has a peduncle
 - Spike orientation
- the spikes are oriented vertically or pressed against the axis
 - Spikes per stem
- 2-15
 - Staminate scale tip
- 
                                
                                    - the staminate scale tip is acute (has a sharp point)
- the staminate scale tip is obtuse (has a blunt point)
 
 - Stigma branching
- the stigmas have three branches
 - Top spike
- the uppermost spike contains only staminate flowers
 
- 
                        Fruits or seeds- Achene dimples
- the achene has no folds or dimples
 - Achene length
- 2.8–3 mm
 - Achene width
- 1.6–1.8 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 flat or M-shaped, with two prominent side-veins
 - Leaf blade length to width ratio
- 7–7.9
 - 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
- there are no corrugations on the leaf sheath
 - Leaf sheath texture
- the leaf sheath feels smooth, and has no hairs
 - Lowest bract sheath
- the lowest bract has a sheath longer than four millimeters
 - Lowest leaf blade width
- 10–25 mm
 - Lowest leaf sheath texture
- the leaf sheath feels smooth (it may have soft hairs)
 - stem leaf blade width
- 2–6 mm
 
- 
                        Place- Habitat
- terrestrial
 - New England state
- 
                                
                                    - Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
 
 - Specific habitat
- 
                                
                                    - forests
- talus or rocky slopes
 
 
- 
                        Stem, shoot, branch- Plant height
- 14–38 cm
 - Relative stem height
- the main stem is taller than the leaves
 - 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
Not classified
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
- uncommon to fairly widespread (S-rank: S3S4)
- Massachusetts
- fairly widespread (S-rank: S4)
From Flora Novae Angliae dichotomous key
25. Carex platyphylla Carey N
broad-leaved sedge. CT, MA, ME, NH, RI, VT. Mesic forests and slopes, usually those underlain by high-pH bedrock.
 
                         
                        ![Leaves: Carex platyphylla. ~ By Arthur Haines. ~ Copyright © 2025 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-239x239/Cyperaceae/carex-platyphylla-le-ahaines.jpg) 
                        ![Leaves: Carex platyphylla. ~ By William Cullina. ~ Copyright © 2025 William Cullina. ~ bill[at]williamcullina.com](https://newfs.s3.amazonaws.com/taxon-images-239x239/Cyperaceae/carex-platyphylla-le-wcullina.jpg) 
                         
                         
                         
                        ![Plant form: Carex platyphylla. ~ By Arthur Haines. ~ Copyright © 2025 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-239x239/Cyperaceae/carex-platyphylla-ha-ahaines-c.jpg) 
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