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Carex hormathodes — marsh straw sedge

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Facts

Marsh straw sedge inhabits Atlantic coast beaches, and saline to fresh-tidal marshes.

Habitat

Brackish or salt marshes and flats, coastal beaches (sea beaches), fresh tidal marshes or flats

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
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
stem leaf blade width
1–3 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 is not borne on a peduncle
Top spike
the uppermost spike contains both staminate and carpellate flowers, with the staminate flowers located below the carpellate flowers
Perigynium hairs
the perigynium has no hairs
Perigynium length
3.8–5.6 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 divided at the top into two teeth
Show all characteristics
  • Flowers

    Bumps on fruit
    • the perigynium surface has papillae on it
    • there are no papillae on the perigynium surface
    Inflorescence length
    25–60 mm
    Length of scale
    the scale is shorter than the perigynium
    Lowest spike length
    6–15 mm
    Lowest spike stalk length
    0 mm
    Lowest spike width
    4–8 mm
    Perigynium beak
    the perigynium has a beak
    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
    • the perigynium beak has tiny serrations along the edges
    Perigynium beak teeth
    the perigynium beak is divided at the top into two teeth
    Perigynium color
    • green
    • tan
    Perigynium cross-section
    • the perigynium is planoconvex (flat on one surface and rounded on the other) in cross-section
    • the perigynium is relatively flat in cross-section
    Perigynium hairs
    the perigynium has no hairs
    Perigynium length
    3.8–5.6 mm
    Perigynium nerve number
    At least 10
    Perigynium nerve texture
    the nerves on the perigynium are raised, even after drying the perigynium
    Perigynium nerves lower side
    At least 5
    Perigynium nerves upper side
    At least 5
    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 obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
    • the perigynium body is ovate (egg-shaped)
    Perigynium width
    1.8–2.8 mm
    Perigynium winged
    the perigynium has wings on it
    Pollen- and seed-producing spikes
    some of the spikes produce perigynia
    Pollen-producing spike length
    0 mm
    Pollen-producing spike number
    0
    Pollen-producing spike peduncle length
    0 mm
    Pollen-producing spike width
    0 mm
    Scale awn
    The carpellate scale does not have an awn (it may have a short point)
    Scale awn texture
    • NA
    • the carpellate scale awn does not have teeth (it may or may not have hairs)
    Scale color
    • green
    • red-brown
    Scale length
    3.5–4.9 mm
    Scale tip
    the carpellate scale tip is acuminate (tapered to a narrow point)
    Spike on stalk
    the lowest spike on the plant is not borne on 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 acuminate (tapered to a narrow point)
    Stigma branching
    the stigmas have two branches
    Top spike
    the uppermost spike contains both staminate and carpellate flowers, with the staminate flowers located below the carpellate flowers
  • Fruits or seeds

    Achene dimples
    the achene has no folds or dimples
    Achene length
    1.5–1.8 mm
    Achene width
    0.7–1.1 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 mostly produced higher up on the plant
    Leaf blade cross-section
    The leaf blade is folded lengthwise, with one prominent midvien
    Leaf blade length to width ratio
    83–140
    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
    Ligule length
    2–4 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
    1–3 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    1–3 mm
  • Place

    Habitat
    wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    Specific habitat
    • brackish or salt marshes and flats
    • fresh tidal marshes or flats
    • sea beaches
  • Stem, shoot, branch

    Plant height
    20–80 cm
    Relative stem height
    the main stem is taller than the leaves
    Spike internode length
    2–18 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

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
present
Vermont
absent

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)
New Hampshire
uncommon (S-rank: S3), W (code: W)

From Flora Novae Angliae dichotomous key

47.  Carex hormathodes Fern. N

marsh straw sedge. Carex straminea Willd. ex Schkuhr var. invisa Boott • CT, MA, ME, NH, RI. Rocky or sandy beaches of the Atlantic coast and bays, and saline to fresh-tidal marshes.

Native to North America?

Yes

Sometimes confused with

Carex straminea:
beak of perigynium spreading, usually more than half of the length of the +/- orbicular body, and staminate portion of lateral spikes 2-6 mm long (vs. C. hormathodes, with beak of perigynium ascending, shorter than half the length of the narrow-ovate body, and staminate portion of lateral spikes shorter than 2 mm).

Synonyms

  • Carex straminea var. invisa Boott

Family

Cyperaceae

Genus

Carex