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Carex prairea — prairie sedge

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Facts

Prairie sedge is found in high-pH fens, in the shade of conifers. It is morphologically similar to lesser tussock sedge (Carex diandra), from which it differs mainly in requiring high pH soils, and in the color of the perigynia, light brown when ripe in prairie sedge, olive-brown to black in lesser tussock sedge.

Habitat

Fens

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
  • Vermont
stem leaf blade width
2–3 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 carpellate flowers located below, or intermixed with, the staminate flowers
Perigynium hairs
the perigynium has no hairs
Perigynium length
2.1–3.3 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

    Bumps on fruit
    there are no papillae on the perigynium surface
    Inflorescence length
    30–90 mm
    Length of scale
    the scale is nearly as long as, or longer than, the perigynium
    Lowest spike stalk length
    0 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    0.8–1.4 mm
    Perigynium beak orientation
    the beak of the perigynium is straight, and in line with the perigynium
    Perigynium beak 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
    • brown
    • tan
    Perigynium 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
    2.1–3.3 mm
    Perigynium nerve number
    At least 6
    Perigynium nerve texture
    the nerves on the perigynium are raised, even after drying the perigynium
    Perigynium nerves lower side
    6–9
    Perigynium nerves upper side
    At least 0
    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 lanceolate (lance-shaped; widest below the middle and tapering at both ends)
    • the perigynium body is ovate (egg-shaped)
    Perigynium width
    1–1.4 mm
    Perigynium winged
    the perigynium has no wings
    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
    Scale color
    red-brown
    Scale length
    2.4–3.3 mm
    Scale tip
    the carpellate scale tip is acute (has a sharp point)
    Spike on stalk
    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 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 both staminate and carpellate flowers, with the carpellate flowers located below, or intermixed with, the staminate flowers
  • Fruits or seeds

    Achene dimples
    the achene has no folds or dimples
    Achene length
    1.2–1.6 mm
    Achene width
    0.7–1 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
    30–166
    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 red dots on the translucent tissues of 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
    1.2–9.2 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
    2–3 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    2–3 mm
  • Place

    Habitat
    wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • Vermont
    Specific habitat
    fens
  • Stem, shoot, branch

    Plant height
    3–100 cm
    Relative stem height
    the main stem is taller than the leaves
    Spike internode length
    7–33 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

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
absent
Rhode Island
absent
Vermont
present

Conservation status

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

Connecticut
rare (S-rank: S2), special concern (code: SC)
Maine
extremely rare (S-rank: S1), threatened (code: T)
Massachusetts
extremely rare (uncertain) (S-rank: S1?)
Vermont
fairly widespread (S-rank: S4)

From Flora Novae Angliae dichotomous key

84.  Carex prairea Dewey ex Wood N

prairie sedge. Carex diandra Schrank var. ramosa (Boott) Fern. • CT, MA, ME, VT. High-pH fens, especially in shade or partial shade of Thuja occidentalis (northern New England) or Larix laricina (southern New England).

Native to North America?

Yes

Sometimes confused with

Carex diandra:
inflorescence more congested, the lowest internode mostly 3-7 mm long, perigynia olive-grown to black, with a pale, depressed stripe on the abaxial surface (vs. C. prairea, with the inflorescence more open, the lowest internode mostly 7-26 mm long, and perigynia light brown, without a pale, depressed stripe on the abaxial surface).

Synonyms

  • Carex diandra Schrank var. ramosa (Boott) Fern.

Family

Cyperaceae

Genus

Carex