Carex laxiculmis — spreading sedge
![Perigynia: Carex laxiculmis. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/carex-laxiculmis-pe-ahaines.jpg)
![Inflorescence: Carex laxiculmis. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/carex-laxiculmis-in-ahaines.jpg)
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Facts
Spreading sedge is a characteristic sedge of evergreen and mixed deciduous forests in New England, often found in wet soil of seeps or next to streams.
Habitat
Forests, shores of rivers or lakes, swamps
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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enlargeCharacteristics
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- stem leaf blade width
- 3–11.8 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
- 2.5–4 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
- 2–3 mm
- Bumps on fruit
- there are no papillae on the perigynium surface
- Length of scale
- the scale is shorter than the perigynium
- Lowest spike length
- 6–20 mm
- Lowest spike stalk length
- 0–90 mm
- Lowest spike width
- 4–6 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
- 2.5–4 mm
- Perigynium nerve number
- At least 16
- Perigynium nerve texture
- the nerves on the perigynium are raised, even after drying the perigynium
- Perigynium nerves lower side
- At least 8
- Perigynium nerves upper side
- At least 8
- 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 elliptic (widest near the middle and tapering at both ends)
- the perigynium body is ovate (egg-shaped)
- Perigynium width
- 1.5–2 mm
- Perigynium winged
- the perigynium has no wings
- Pollen- and seed-producing spikes
- some of the spikes produce perigynia
- Pollen-producing spike length
- 8–22 mm
- Pollen-producing spike number
- 1
- Pollen-producing spike peduncle length
- 0–95 mm
- Pollen-producing spike width
- 1–2.7 mm
- Scale awn
- the carpellate scale has an awn on it
- Scale awn texture
- the carpellate scale awn does not have teeth (it may or may not have hairs)
- Scale color
- green
- Scale length
- 2.5–3.2 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 bent downwards or droop downwards
- Spikes per stem
- 2-15
- Staminate scale tip
- the staminate scale tip is acute (has a sharp 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
- 2.2–3.2 mm
- Achene width
- 1.2–1.8 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
- 27–30
- 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
- 3–11.8 mm
- Lowest leaf sheath texture
- the leaf sheath feels smooth (it may have soft hairs)
- stem leaf blade width
- 3–11.8 mm
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- forests
- shores of rivers or lakes
- swamps
-
Stem, shoot, branch
- Plant height
- 9–48 cm
- Relative stem height
-
- the main stem is equal to or shorter than the leaves
- 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
- rare (S-rank: S2), endangered (code: E)
- Vermont
- uncommon (S-rank: S3)
var. copulata
- Massachusetts
- unranked (S-rank: SNR)
var. laxiculmis
- Massachusetts
- widespread (S-rank: S5)
- New Hampshire
- unrankable (S-rank: SU), Ind (code: Ind)
Subspecies and varieties
Our variety is Carex laxiculmis Schwein. var. laxiculmis.
From Flora Novae Angliae dichotomous key
23. Carex laxiculmis Schwein. var. laxiculmis N
spreading sedge. CT, MA, ME, NH, RI, VT. Deciduous and mixed evergreen-deciduous forests, often adjacent to streams or seepage areas, sometimes in rich, mesic types. Carex laxiculmis var. copulata (Bailey) Fern. was reported from MA by Sorrie and Somers (1999), but specimens are unknown.
Native to North America?
Yes
Sometimes confused with
- Carex abscondita:
- staminate spikes mostly 0.6-1.4 mm wide, staminate scales obtuse at the apex, mostly 2.6-3.6 mm long, and vegetative shoots much taller than the flowering stems (vs. C. laxiculmis, with staminate spikes 1.2-2.7 mm wide, staminate scales acute at apex, 3.3-4.5 mm long, and vegetative shoots shorter than to slightly taller than flowering stems).
- Carex digitalis:
- leaf blades green and lowest scales on lateral spikes subtending perigynia (vs. C. laxiculmis, with leaves blades glaucous and lowest scales on lateral spikes without perigynia).