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Carex intumescens — greater bladder sedge

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Facts

Greater bladder sedge has lustrous, inflated, tear-drop shaped perigynia (sacs enclosing the fruits). It is similar to Gray's sedge (Carex grayi), but the latter has spikes with perigynia that radiate in all directions, whereas in greater bladder sedge they point upwards to outwards, but usually not downwards.

Habitat

Forests, wetland margins (edges of wetlands)

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
  • terrestrial
  • wetlands
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
stem leaf blade width
3.5–8 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
Top spike
the uppermost spike contains only staminate flowers
Perigynium hairs
the perigynium has no hairs
Perigynium length
10–16.5 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 divided at the top into two teeth
Show all characteristics
  • Flowers

    Anther length
    2–4 mm
    Bumps on fruit
    there are no papillae on the perigynium surface
    Inflorescence length
    20–150 mm
    Length of scale
    the scale is shorter than the perigynium
    Lowest spike length
    10–27 mm
    Lowest spike stalk length
    3–15 mm
    Lowest spike width
    10–28 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    1.5–4.2 mm
    Perigynium beak orientation
    the beak of the perigynium is straight, and in line with the perigynium
    Perigynium beak serrations
    the perigynium beak has no serrations
    Perigynium beak teeth
    the perigynium beak is divided at the top into two teeth
    Perigynium beak teeth length
    Up to 1 mm
    Perigynium color
    • green
    • tan
    Perigynium cross-section
    the perigynium is relatively round in cross-section
    Perigynium hairs
    the perigynium has no hairs
    Perigynium length
    10–16.5 mm
    Perigynium nerve number
    13–23
    Perigynium nerve texture
    the nerves on the perigynium are raised, even after drying the perigynium
    Perigynium nerves lower side
    6–11
    Perigynium nerves upper side
    6–11
    Perigynium orientation
    • the perigynia are angled outwards
    • the perigynia are curved or bent downwards or backwards along the axis
    • the perigynia are oriented vertically or pressed against the axis or adjacent perigynia
    Perigynium puffy
    the perigynium is inflated (there is space between the perigynium and the achene)
    Perigynium shape
    • the perigynium body is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
    • the perigynium body is ovate (egg-shaped)
    Perigynium width
    2.5–6.5 mm
    Perigynium winged
    the perigynium has no wings
    Pollen- and seed-producing spikes
    some of the spikes produce perigynia
    Pollen-producing spike length
    10–50 mm
    Pollen-producing spike number
    1
    Pollen-producing spike peduncle length
    5–40 mm
    Pollen-producing spike width
    1–3 mm
    Scale awn
    the carpellate scale has an awn on it
    Scale awn texture
    the carpellate scale awn has tiny teeth
    Scale color
    • green
    • white or translucent
    Scale length
    4–9.5 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 acuminate (tapered to a narrow point)
    • 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
    3.5–5.7 mm
    Achene width
    2.2–3.9 mm
    Style persistence
    the style stays on 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 folded lengthwise, with one prominent midvien
    Leaf blade length to width ratio
    23–34
    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
    • the upper surface of the leaf blade has papillae on it
    Leaf sheath bumps
    • the top edge of the leaf sheath has papillae on it
    • 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
    Ligule length
    1–8 mm
    Lowest bract sheath
    the lowest bract has no sheath (or a very short sheath up to four millimeters in length)
    Lowest leaf blade width
    3.5–8 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    3.5–8 mm
  • Place

    Habitat
    • terrestrial
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • edges of wetlands
    • forests
  • Stem, shoot, branch

    Plant height
    15–140 cm
    Relative stem height
    • the main stem is equal to or shorter than the leaves
    • the main stem is taller than the leaves
    Spike internode length
    2–21 mm
    Stem cross-section
    the main stem is roughly triangular in cross-section
    Stem spacing
    • the stems grow close together in compact clusters or tufts
    • 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
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
unranked (S-rank: SNR)
Massachusetts
widespread (S-rank: S5)

From Flora Novae Angliae dichotomous key

110.  Carex intumescens Rudge N

greater bladder sedge. Carex intumescens Rudge var. fernaldii Bailey • CT, MA, ME, NH, RI, VT. Mesic to hydric forests and wetland edges.

Native to North America?

Yes

Sometimes confused with

Carex grayi:
carpellate spikes spherical, with 8-35 perigynia radiating in all directions, and perigynium base cuneate (vs. C. intumescens, with carpellate spikes mostly short-ovoid, with mostly 1-12 ascending to spreading perigynia, and perigynium base convexly rounded).

Synonyms

  • Carex intumescens var. fernaldii Bailey

Family

Cyperaceae

Genus

Carex