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Carex tenuiflora — sparse-flowered sedge

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Facts

Sparse-flowered sedge is a circumboreal species, but rare in New England, being mostly confined to white cedar (Thuja occidentalis) fens in Maine, New Hampshire and Vermont.

Habitat

Fens (calcium-rich 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
wetlands
New England state
  • Maine
  • New Hampshire
  • Vermont
Leaf blade width
0.5–2 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 staminate flowers located below the carpellate flowers
Perigynium hairs
the perigynium has no hairs
Perigynium length
3–3.5 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
NA
Show all characteristics
  • Flowers

    Bumps on fruit
    the perigynium surface has papillae on it
    Inflorescence length
    6–12 mm
    Length of scale
    the scale is nearly as long as, or longer than, the perigynium
    Lowest spike length
    4–9 mm
    Lowest spike stalk length
    0 mm
    Lowest spike width
    3–6 mm
    Perigynium beak
    the perigynium has no beak, or an extremely short beak
    Perigynium beak length
    0 mm
    Perigynium beak orientation
    NA
    Perigynium beak serrations
    NA
    Perigynium beak teeth
    NA
    Perigynium beak teeth length
    0 mm
    Perigynium color
    green
    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
    3–3.5 mm
    Perigynium nerve texture
    the nerves on the perigynium are raised, even after drying the perigynium
    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 oblong (rectangular but with rounded ends)
    Perigynium width
    1.5–1.75 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
    white or translucent
    Scale tip
    the carpellate scale tip is obtuse (has a blunt point)
    Spike on stalk
    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
    Stigma branching
    the stigmas have two branches
    Top spike
    the uppermost spike contains both staminate and carpellate flowers, with the staminate flowers located below the carpellate flowers
  • Fruits or seeds

    Achene dimples
    the achene has no folds or dimples
    Achene length
    1.5–2 mm
    Achene width
    1.25–1.5 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 folded lengthwise, with one prominent midvien
    • the leaf blade is flat or M-shaped, with two prominent side-veins
    Leaf blade length to width ratio
    75–100
    Leaf blade texture
    the leaf blade is smooth and hairless, or rough and sandpapery
    Leaf blade width
    0.5–2 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 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
    0.5–2 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
  • Place

    Habitat
    wetlands
    New England state
    • Maine
    • New Hampshire
    • Vermont
    Specific habitat
    fens (calcium-rich wetlands)
  • Stem, shoot, branch

    Plant height
    10–50 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

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

In New England

Distribution

Connecticut
absent
Maine
present
Massachusetts
absent
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.

Maine
uncommon (S-rank: S3), special concern (code: SC)
Massachusetts
unranked (S-rank: SNR)
New Hampshire
extremely rare (S-rank: S1), endangered (code: E)
Vermont
extremely rare (S-rank: S1)

From Flora Novae Angliae dichotomous key

72.  Carex tenuiflora Wahlenb. NC

sparse-flowered sedge. ME, NH, VT; also reported from MA by Toivonen (2002), but specimens are unknown. Fens, usually in the shade of Thuja occidentalis.

72×73. Carex tenuiflora × Carex trisperma Carex ×‌trichina Fern. is a rare sedge hybrid known from ME. Characteristics that distinguish this plant are its short-beaked perigynia and less congested inflorescence (compared with C. tenuiflora).

Native to North America?

Yes

Sometimes confused with

Carex leptalea

Family

Cyperaceae

Genus

Carex