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Carex torta — twisted sedge

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New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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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

Characteristics

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
Show all characteristics

  • 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)

New England distribution and conservation status

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)

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

Family

Cyperaceae

Genus

Carex

Help

From the dichotomous key of Flora Novae Angliae

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.