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Carex tetanica — rigid sedge

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Facts

Rigid sedge grows in mainly calcareous fens and wet meadows in Connecticut, Massachusetts and New Hampshire.

Habitat

Fens, marshes, meadows and fields

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
wetlands
New England state
  • Connecticut
  • Massachusetts
  • New Hampshire
stem leaf blade width
1.5–5 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
  • 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
    the perigynium surface has papillae on it
    Inflorescence length
    40–320 mm
    Length of scale
    the scale is shorter than the perigynium
    Lowest spike length
    6–40 mm
    Lowest spike width
    3–5.8 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    Up to 0.5 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
    • brown
    • yellow
    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 texture
    the nerves on the perigynium are raised, even after drying the perigynium
    Perigynium orientation
    • the perigynia are angled outwards
    • 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
    1–1.2 mm
    Perigynium winged
    the perigynium has no wings
    Pollen- and seed-producing spikes
    some of the spikes produce perigynia
    Pollen-producing spike number
    1
    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
    • brown
    • purple to black
    Scale tip
    the carpellate scale tip is obtuse (has a blunt 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
    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
    1.8–3 mm
    Achene width
    1.2–1.8 mm
    Style persistence
    the style falls off the mature achenes

  • Growth form

    Rhizomes
    there are long rhizomes present

  • 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
    20–40
    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
    • 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
    Ligule length
    0.6–6 mm
    Lowest bract sheath
    the lowest bract has a sheath longer than four millimeters
    Lowest leaf blade width
    1.5–5 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    1.5–5 mm

  • Place

    Habitat
    wetlands
    New England state
    • Connecticut
    • Massachusetts
    • New Hampshire
    Specific habitat
    • fens
    • marshes
    • meadows or fields

  • Stem, shoot, branch

    Plant height
    15–65 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 singly or a few together (they may form diffuse colonies)

Wetland status

Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)

In New England

Distribution

Connecticut
present
Maine
absent
Massachusetts
present
New Hampshire
present
Rhode Island
absent
Vermont
absent

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Connecticut
uncommon (S-rank: S3)
Massachusetts
uncommon (S-rank: S3), special concern (code: SC)
New Hampshire
extirpated (S-rank: SX), X (code: X)

From Flora Novae Angliae dichotomous key

128.  Carex tetanica Schkuhr NC

rigid sedge. CT, MA, NH; also reported from RI by Magee and Ahles (1999), but specimens are unknown. Circumneutral fens, meadows, and graminoid marshes. Reports of Carex woodii Dewey in New England (e.g., Dowhan 1979, Seymour 1982) were based, in large part, on specimens of C. tetanica that showed slight anthocyanic suffusion of the lower, bladeless sheaths and shallow rhizomes. However, C. woodii shows deep anthocyanic suffusion of the lower, bladeless sheaths and shallow, relatively stout rhizomes that emit aerial shoots at ± regular intervals. Further, the specimens were collected from fens (typical for C. tetanica, atypical for C. woodii).

Native to North America?

Yes

Sometimes confused with

Carex meadii:
achenes mostly 1.7-2.2 mm wide and leaves with gray-green blades and ligules 0.4-3.6 mm long (vs. C. tetanica, with achenes mostly 1.2-1.6 mm wide and leaves with green blades and ligules mostly 1-6 mm long).
Carex panicea:
stems smooth on the angles and lowermost bract of inflorescence short, the blade and sheath 28-58% as long as the inflorescence (vs. C. tetanica, with stems scabrous on the angles, at least near the summit, and lowermost bract of inflorescence elongate, the blade and sheath 62-111% as long as the inflorescence).

Family

Cyperaceae

Genus

Carex