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Carex conoidea — open-field sedge

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Facts

Individuals of open-field sedge that appear dwarfed can be found in the northern portion of its range and in habitats where water levels fluctuate rapidly.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields, shores of rivers or lakes

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
2.3–5.6 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
  • 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
2.5–4.3 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 not divided at the tip into two teeth, or the teeth are very tiny
Show all characteristics

  • Flowers

    Anther length
    1.8–3.6 mm
    Bumps on fruit
    there are no papillae on the perigynium surface
    Length of scale
    the scale is shorter than the perigynium
    Lowest spike length
    5–29 mm
    Lowest spike stalk length
    At least 0 mm
    Lowest spike width
    3.1–10.2 mm
    Perigynium beak
    the perigynium has no beak, or an extremely short beak
    Perigynium beak length
    0–0.2 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 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 relatively round in cross-section
    Perigynium hairs
    the perigynium has no hairs
    Perigynium length
    2.5–4.3 mm
    Perigynium nerve number
    17–25
    Perigynium nerve texture
    the nerves on the perigynium are flat or concave after drying
    Perigynium nerves lower side
    8–12
    Perigynium nerves upper side
    8–12
    Perigynium orientation
    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 oblong (rectangular but with rounded ends)
    • 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
    1.2–1.8 mm
    Perigynium winged
    the perigynium has no wings
    Pollen- and seed-producing spikes
    some of the spikes produce perigynia
    Pollen-producing spike length
    5–30 mm
    Pollen-producing spike number
    1
    Pollen-producing spike peduncle length
    2.9–103 mm
    Pollen-producing spike width
    1–4.2 mm
    Scale awn
    the carpellate scale has an awn on it
    Scale awn texture
    the carpellate scale awn has tiny teeth
    Scale color
    • red-brown
    • white or translucent
    Scale length
    2.4–4.7 mm
    Scale tip
    the carpellate scale tip is acuminate (tapered to a narrow 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 oriented vertically or pressed against the axis
    Spikes per stem
    2-15
    Staminate scale tip
    the staminate scale tip is obtuse (has a blunt 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
    1.8–2.6 mm
    Achene width
    1–1.4 mm
    Style persistence
    the style falls off the mature achenes

  • Growth form

    Rhizomes
    • there are long rhizomes present
    • 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 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 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
    0.8–3.7 mm
    Lowest bract sheath
    the lowest bract has a sheath longer than four millimeters
    Lowest leaf blade width
    2.3–5.6 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    2.3–5.6 mm

  • Place

    Habitat
    • terrestrial
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields
    • shores of rivers or lakes

  • Stem, shoot, branch

    Plant height
    2–75 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

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

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
widespread (S-rank: S5)
Massachusetts
widespread (S-rank: S5)

From Flora Novae Angliae dichotomous key

78.  Carex conoidea Schkuhr ex Willd. N

open-field sedge. Carex katahdinensis Fern. • CT, MA, ME, NH, RI, VT. Meadows, river shores, lake shores, and open, wet, disturbed ground. Carex katahdinensis represents dwarfed individuals of C. conoidea that occur on northern ponds with fluctuating water levels. The dwarf stature appears to represent an adaptation for rapid completion of reproduction. Some specimens of C. conoidea with relatively fewer flowers in the spikes, especially those missing the basal leaf sheaths, can be confused with specimens of C. grisea. However, C. conoidea has narrower perigynia—(1.2–) 1.3–1.7 (–1.8) mm wide—and prominently scabrous staminate spike peduncles, whereas the perigynia of C. grisea are wider—(1.8–) 2–2.6 mm wide—and have a smooth or sparsely scabrous staminate spike peduncle. Carex conoidea is the only member of its section that routinely occurs in open habitats.

Native to North America?

Yes

Sometimes confused with

Carex glaucodea:
peduncles of lateral spikes smooth and leaf blades very glaucous (vs. C. conoidea, with peduncles of lateral spikes scaberulous and leaf blades green).

Synonyms

  • Carex katahdinensis Fern.

Family

Cyperaceae

Genus

Carex