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Carex lenticularis — lake shore sedge

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Facts

Lake shore sedge is a common species of lake and stream shorelines, especially when they are sandy, gravelly or rocky. The perigynia typically have 5 to 7 veins on each surface, and the lowest bract of the inflorescence is usually much longer than the entire inflorescence.

Habitat

Alpine or subalpine zones, shores of rivers or lakes, wetland margins (edges of wetlands)

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
  • Maine
  • Massachusetts
  • New Hampshire
  • Vermont
stem leaf blade width
1.5–3.5 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 has a peduncle
Top spike
the uppermost spike contains only staminate flowers
Perigynium hairs
the perigynium has no hairs
Perigynium length
1.7–3.2 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

    Bumps on fruit
    the perigynium surface has papillae on it
    Length of scale
    the scale is shorter than the perigynium
    Lowest spike length
    12–60 mm
    Lowest spike stalk length
    At least 10 mm
    Lowest spike width
    2–4 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    0.1–0.2 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
    green
    Perigynium cross-section
    • the perigynium is biconvex (convexly rounded on both sides, like a lens) in 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
    1.7–3.2 mm
    Perigynium nerve number
    6–14
    Perigynium nerve texture
    the nerves on the perigynium are raised, even after drying the perigynium
    Perigynium nerves lower side
    3–7
    Perigynium nerves upper side
    3–7
    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 elliptic (widest near the middle and tapering at both ends)
    • the perigynium body is ovate (egg-shaped)
    Perigynium width
    1–1.6 mm
    Perigynium winged
    the perigynium has no wings
    Pollen- and seed-producing spikes
    some of the spikes produce perigynia
    Pollen-producing spike number
    1
    Scale awn
    The carpellate scale does not have an awn (it may have a short point)
    Scale awn texture
    NA
    Scale color
    • brown
    • red-brown
    Scale tip
    the carpellate scale tip is obtuse (has a blunt 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
    Staminate scale tip
    • the staminate scale tip is obtuse (has a blunt point)
    • the staminate scale tip is rounded to retuse (blunt or rounded, with a notch at the tip)
    Stigma branching
    the stigmas have two branches
    Top spike
    the uppermost spike contains only staminate flowers

  • Fruits or seeds

    Achene dimples
    the achene has no folds or dimples
    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 all produced from the base of the plant
    Leaf blade cross-section
    The leaf blade is folded lengthwise, with one prominent midvien
    Leaf blade texture
    the leaf blade is smooth and hairless, or rough and sandpapery
    Leaf bumps
    the upper surface of the leaf blade has papillae on it
    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
    Lowest bract sheath
    the lowest bract has no sheath (or a very short sheath up to four millimeters in length)
    Lowest leaf blade width
    1.5–3.5 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    1.5–3.5 mm

  • Place

    Habitat
    • terrestrial
    • wetlands
    New England state
    • Maine
    • Massachusetts
    • New Hampshire
    • Vermont
    Specific habitat
    • alpine or subalpine zones
    • edges of wetlands
    • shores of rivers or lakes

  • Stem, shoot, branch

    Plant height
    8–60 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 close together in compact clusters or tufts

Wetland status

Occurs only in wetlands. (Wetland indicator code: OBL)

In New England

Distribution

Connecticut
absent
Maine
present
Massachusetts
present
New Hampshire
present
Rhode Island
absent
Vermont
present

Conservation status

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

Massachusetts
rare (S-rank: S2), threatened (code: T)
Vermont
rare to uncommon (S-rank: S2S3)

From Flora Novae Angliae dichotomous key

136.  Carex lenticularis Michx. N

lake shore sedge. Carex lenticularis Michx. var. albimontana Dewey; C. lenticularis Michx. var. blakei Dewey • MA, ME, NH, VT. Shorelines, often those of high mineral content (e.g., sand, gravel, stone), including moderately high elevation tarns.

Native to North America?

Yes

Sometimes confused with

Carex aquatilis:
leaf blades 2.5-8 mm wide and perigynia without veins or with 1-4 obscure veins on one surface (vs. C. lenticularis, with leaf blades 1.5-3.5 mm wide and perigynia with mostly 5-7 veins on each surface).
Carex torta:
lowermost spike arching to dropping, and perigynia smooth, veinless, with a triangular apex that is often twisted (vs. C. lenticularis, with the lowermost spike erect to ascending, and perigynia minutely papillose, with 3-5 veins on each surface, with an acute to obtuse apex that is plane).

Synonyms

  • Carex lenticularis Michx. var. albimontana Dewey
  • Carex lenticularis Michx. var. blakei Dewey

Family

Cyperaceae

Genus

Carex