Carex torta — twisted sedge
![Inflorescence: Carex torta. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/carex-torta-in-ahaines.jpg)
![Plant form: Carex torta. ~ By Ben Kimball. ~ Copyright © 2024 Ben Kimball. ~ alpinefin[at]comcast.net](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/carex-torta-ha-bkimball.jpg)
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Facts
Twisted sedge is a specialist of rocky and gravelly river shores and stream banks. Its name refers to the triangular flat tip in the apex of the perigynium, which is often twisted.
Habitat
Shores of rivers or lakes
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
- Vermont
- stem leaf blade width
- 3–5 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 has a peduncle
- the lowest spike on the plant is not borne on a peduncle
- Top spike
- the uppermost spike contains only staminate flowers
- Perigynium hairs
- the perigynium has no hairs
- Perigynium length
- 2.3–4.7 mm
- Leaf sheath color
- the leaf sheath is tinted pink, red or purple
- 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
- Bumps on fruit
- there are no papillae on the perigynium surface
- Length of scale
- the scale is shorter than the perigynium
- Lowest spike length
- 25–90 mm
- Lowest spike stalk length
- At least 0 mm
- Lowest spike width
- 4–5 mm
- Perigynium beak
- the perigynium has a beak
- Perigynium beak length
- 0.1–0.3 mm
- 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 biconvex (convexly rounded on both sides, like a lens) in 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
- 2.3–4.7 mm
- Perigynium nerve number
- 0
- Perigynium nerve texture
- NA
- Perigynium nerves lower side
- 0
- Perigynium nerves upper side
- 0
- Perigynium orientation
- the perigynia are angled outwards
- Perigynium puffy
- the perigynium is inflated (there is space between the perigynium and the achene)
- Perigynium shape
- the perigynium body is ovate (egg-shaped)
- Perigynium width
- 1.1–1.8 mm
- Perigynium winged
- the perigynium has no wings
- Pollen- and seed-producing spikes
- some of the spikes produce perigynia
- Pollen-producing spike length
- 20–40 mm
- Pollen-producing spike number
- 1–2
- Scale awn
- The carpellate scale does not have an awn (it may have a short point)
- Scale awn texture
- NA
- Scale color
-
- brown
- purple to black
- Scale tip
- the carpellate scale tip is acute (has a sharp point)
- Spike on stalk
-
- the lowest spike on the plant has a peduncle
- the lowest spike on the plant is not borne on a peduncle
- Spike orientation
-
- the spikes are angled outwards, or arched over
- the spikes are bent downwards or droop downwards
- 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 only staminate flowers
-
Fruits or seeds
- Achene dimples
- the achene has no folds or dimples
- Style persistence
- the style falls off the mature achenes
-
Growth form
- Rhizomes
- there are long rhizomes present
-
Leaves
- Leaf arrangement
- the leaves are mostly produced higher up on the plant
- Leaf blade cross-section
- the leaf blade is flat or M-shaped, with two prominent side-veins
- 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 is tinted pink, red or purple
- 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 no sheath (or a very short sheath up to four millimeters in length)
- Lowest leaf blade width
- 3–5 mm
- Lowest leaf sheath texture
- the leaf sheath feels smooth (it may have soft hairs)
- stem leaf blade width
- 3–5 mm
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Specific habitat
- shores of rivers or lakes
-
Stem, shoot, branch
- Plant height
- 25–75 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
Occurs only in wetlands. (Wetland indicator code: OBL)
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)
From Flora Novae Angliae dichotomous key
142. Carex torta Boott ex Tuckerman N
twisted sedge. Carex acuta L. var. sparsiflora Dewey; C. torta Boott ex Tuckerman var. composita Porter • CT, MA, ME, NH, VT; also reported from RI by George (1992), but specimens are unknown. Rocky and gravelly river shores and stream banks.
Native to North America?
Yes
Sometimes confused with
- Carex lenticularis:
- lowermost spike erect to ascending, and perigynia minutely papillose, with 3-5 veins on each surface, with an acute to obtuse apex that is plane (vs. C. torta, with the lowermost spike arching to dropping, and perigynia smooth, veinless, with a triangular apex that is often twisted).
Synonyms
- Carex acuta L. var. sparsiflora Dewey
- Carex torta Boott ex Tuckerman var. composita Porter