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Native Plant Trust: Go Botany Discover thousands of New England plants

Carex polymorpha — variable sedge

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Facts

With a restricted distribution on well-drained sandy soils from Maine to Virginia along the Eastern Seaboard, variable sedge is rare or endangered in most New England states, and has been a candidate for Federal listing, withdrawn after additional populations were found. Still, there are probably fewer than 45 populations in the world, about a third of them in New England. A few of these populaions are very large, covering many acres. It typically occurs in sandy, acidic soils with seasonal flooding or near wetlands.

Habitat

Anthropogenic (man-made or disturbed habitats), forest edges, woodlands

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
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
Leaf blade width
2.5–6 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
Top spike
the uppermost spike contains only staminate flowers
Perigynium hairs
the perigynium has no hairs
Perigynium length
4.2–6.8 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
    the perigynium surface has papillae on it
    Inflorescence length
    60–190 mm
    Length of scale
    the scale is shorter than the perigynium
    Lowest spike length
    15–35 mm
    Lowest spike width
    7.5–11 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    0.6–1.8 mm
    Perigynium beak orientation
    • the beak of the perigynium is curved, or angled out from the perigynium
    • 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 color
    • brown
    • yellow
    Perigynium cross-section
    the perigynium is relatively round in cross-section
    Perigynium hairs
    the perigynium has no hairs
    Perigynium length
    4.2–6.8 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 perigynium is inflated (there is space between the perigynium and the achene)
    Perigynium shape
    the perigynium body is elliptic (widest near the middle and tapering at both ends)
    Perigynium width
    1.5–2.5 mm
    Perigynium winged
    the perigynium has no wings
    Pollen- and seed-producing spikes
    some of the spikes produce perigynia
    Pollen-producing spike length
    10–30 mm
    Pollen-producing spike number
    1–3
    Scale awn
    The carpellate scale does not have an awn (it may have a short point)
    Scale awn texture
    NA
    Scale color
    • brown
    • purple to black
    Scale tip
    • the carpellate scale tip is obtuse (has a blunt point)
    • the carpellate scale tip is rounded to retuse (blunt or rounded, with a notch at the tip)
    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
    2.2–2.8 mm
    Achene width
    1.4–2.3 mm
    Style persistence
    the style falls off the mature achenes

  • Growth form

    Rhizomes
    there are long rhizomes present

  • Leaves

    Leaf arrangement
    the leaves are mostly produced higher up on 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
    16–75
    Leaf blade texture
    the leaf blade is smooth and hairless, or rough and sandpapery
    Leaf blade width
    2.5–6 mm
    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 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
    2–10 mm
    Lowest bract sheath
    the lowest bract has a sheath longer than four millimeters
    Lowest leaf blade width
    2.5–6 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)

  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    Specific habitat
    • edges of forests
    • man-made or disturbed habitats
    • woodlands

  • Stem, shoot, branch

    Plant height
    30–60 cm
    Relative stem height
    • the main stem is equal to or shorter than the leaves
    • 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 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
absent

Conservation status

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

Connecticut
extremely rare (S-rank: S1), endangered (code: E)
Maine
extremely rare (S-rank: S1), endangered (code: E)
Massachusetts
rare (S-rank: S2), endangered (code: E)
New Hampshire
extremely rare (S-rank: S1), endangered (code: E)
Rhode Island
extremely rare (S-rank: S1), state endangered (code: SE)

From Flora Novae Angliae dichotomous key

127.  Carex polymorpha Muhl. NC

variable sedge. CT, MA, ME, NH, RI. Sandy soils of woodlands, forest edges, borrow pits, and cleared rights-of-way.

Native to North America?

Yes

Sometimes confused with

Carex vaginata

Family

Cyperaceae

Genus

Carex