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Carex hirta — hammer sedge

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New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Facts

Hammer sedge is a non-native sedge, introduced from Eurasia and first collected in the United States in 1877 in Amherst, Massachusetts. It tolerates a variety of moisture levels, and as is typical for an introduced species, usually inhabits human-disturbed sites.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • Vermont
stem leaf blade width
2.5–8 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 is hairy
Perigynium length
4.8–7.8 mm
Leaf sheath color
the leaf sheath is tinted pink, red or purple
Leaf blade texture
the leaf blade is hairy
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
    80–500 mm
    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
    20–50 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    1.5–2.7 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 divided at the top into two teeth
    Perigynium beak teeth length
    0.8–1.7 mm
    Perigynium color
    • green
    • orange to orange-brown
    Perigynium cross-section
    • the perigynium is relatively round in cross-section
    • the perigynium is trigonous (triangular) in cross-section
    Perigynium hairs
    the perigynium is hairy
    Perigynium length
    4.8–7.8 mm
    Perigynium nerve number
    12–20
    Perigynium nerve texture
    the nerves on the perigynium are raised, even after drying the perigynium
    Perigynium nerves lower side
    6–10
    Perigynium nerves upper side
    6–10
    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 ovate (egg-shaped)
    Perigynium width
    1.7–2.5 mm
    Perigynium winged
    the perigynium has no wings
    Pollen- and seed-producing spikes
    some of the spikes produce perigynia
    Pollen-producing spike length
    20–30 mm
    Pollen-producing spike number
    1–3
    Pollen-producing spike peduncle length
    At least 0 mm
    Scale awn
    the carpellate scale has an awn on it
    Scale awn texture
    the carpellate scale awn has tiny teeth
    Scale color
    • green
    • tan
    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
    Staminate scale tip
    • the staminate scale tip is acuminate (tapered to a narrow point)
    • the staminate scale tip is acute (has a sharp point)
    • the staminate scale tip is obtuse (has a blunt point)
    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
    Style persistence
    the style stays on 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 texture
    the leaf blade is hairy
    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 rough, or has hairs
    Ligule length
    2–10.5 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
    2.5–8 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    2.5–8 mm
  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • Vermont
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields
  • Stem, shoot, branch

    Plant height
    10–90 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

Not classified

New England distribution and conservation status

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.

Massachusetts
not applicable (S-rank: SNA)

Native to North America?

No

Sometimes confused with

Carex atherodes:
perigynia glabrous and leaf blades minutely papillose on the abaxial surface (vs. C. hirta, with perigynia pubescent and leaf blades not minutely papillose).
Carex trichocarpa:
leaf sheaths and blades glabrous and floral scales glabrous (vs. C. hirta, with leaf sheaths and blades pubescent and staminate and often carpellate scales pubescent).

Family

Cyperaceae

Genus

Carex

From the dichotomous key of Flora Novae Angliae

19.  Carex hirta L. E

hammer sedge. CT, MA, ME, VT. Fields, ditches, railroad embankments, roadsides, and other human-disturbed sites on a variety of soil moisture regimes.