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Carex oligocarpa — rich woods sedge

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Facts

Rich woods sedge is endangered in Connecticut and Vermont, and found also in Massachusetts. It is more frequent outside New England, especially in the midwest. It occupies rich, high-pH, rocky forests and woodlands.

Habitat

Forests, 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
  • Massachusetts
  • Vermont
stem leaf blade width
1.8–4.6 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
3.7–4.7 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 not divided at the tip into two teeth, or the teeth are very tiny
Show all characteristics

  • Flowers

    Anther length
    2.8–3.5 mm
    Bumps on fruit
    there are no papillae on the perigynium surface
    Length of scale
    • the scale is nearly as long as, or longer than, the perigynium
    • the scale is shorter than the perigynium
    Lowest spike length
    4–19 mm
    Lowest spike width
    3.8–9.2 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    0.4–1.2 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 trigonous (triangular) in cross-section
    Perigynium hairs
    the perigynium has no hairs
    Perigynium length
    3.7–4.7 mm
    Perigynium nerve number
    51–67
    Perigynium nerve texture
    the nerves on the perigynium are flat or concave after drying
    Perigynium nerves lower side
    25–33
    Perigynium nerves upper side
    25–33
    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 elliptic (widest near the middle and tapering at both ends)
    • the perigynium body is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
    Perigynium width
    1.6–2 mm
    Perigynium winged
    the perigynium has no wings
    Pollen- and seed-producing spikes
    some of the spikes produce perigynia
    Pollen-producing spike length
    7–45 mm
    Pollen-producing spike number
    1
    Pollen-producing spike peduncle length
    2.6–113 mm
    Pollen-producing spike width
    0.9–3.1 mm
    Scale awn
    the carpellate scale has an awn on it
    Scale awn texture
    the carpellate scale awn has tiny teeth
    Scale color
    white or translucent
    Scale length
    2.8–6.8 mm
    Scale tip
    • the carpellate scale tip is acuminate (tapered to a narrow point)
    • 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
    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
    2.8–3.4 mm
    Achene width
    1.5–1.8 mm
    Style persistence
    the style falls off the mature achenes

  • Growth form

    Rhizomes
    there are long rhizomes present

  • 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 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
    0.8–6.4 mm
    Lowest bract sheath
    the lowest bract has a sheath longer than four millimeters
    Lowest leaf blade width
    1.8–4.6 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    1.8–4.6 mm

  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Massachusetts
    • Vermont
    Specific habitat
    • forests
    • woodlands

  • Stem, shoot, branch

    Plant height
    10–55 cm
    Relative stem height
    the main stem is equal to or shorter 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

Not classified

In New England

Distribution

Connecticut
present
Maine
absent
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)
Massachusetts
extremely rare (S-rank: S1), endangered (code: E)
Vermont
extremely rare (S-rank: S1), endangered (code: E)

From Flora Novae Angliae dichotomous key

82.  Carex oligocarpa Schkuhr ex Willd. NC

rich woods sedge. CT, MA, VT. Rich, mesic to dry-mesic, often rocky, forests and woodlands in high-pH bedrock regions.

Native to North America?

Yes

Sometimes confused with

Carex grisea:
widest leaf blades mostly 4.2-8.2 mm wide and beak of perigynium 0-0.2 mm long (vs. C. oligocarpa, with widest leaf blades mostly 2.4-4 mm wide and beak of perigynium 0.4-1.2 mm long).

Family

Cyperaceae

Genus

Carex