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Carex atlantica — prickly bog sedge

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Facts

There are two varieties of prickly bog sedge in our region. Despite living in similar habitat and flowering at the same time, the two varieties (Carex atlantica var. atlantica and C. atlantica var. capillacea) remain distinct in New England.

Habitat

Bogs, swamps, 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
wetlands
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Leaf blade width
0.65–4.5 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 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
1.9–3.8 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 divided at the top into two teeth
Show all characteristics
  • Flowers

    Anther length
    0.6–1.8 mm
    Bumps on fruit
    there are no papillae on the perigynium surface
    Inflorescence length
    8–55 mm
    Length of scale
    the scale is shorter than the perigynium
    Lowest spike length
    3.1–13.1 mm
    Lowest spike stalk length
    0 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    0.4–0.95 mm
    Perigynium beak orientation
    the beak of the perigynium is straight, and in line with the perigynium
    Perigynium beak serrations
    the perigynium beak has tiny serrations along the edges
    Perigynium beak teeth
    the perigynium beak is divided at the top into two teeth
    Perigynium beak teeth length
    0.15–0.45 mm
    Perigynium color
    brown
    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
    1.9–3.8 mm
    Perigynium nerve number
    7–23
    Perigynium nerve texture
    the nerves on the perigynium are raised, even after drying the perigynium
    Perigynium nerves lower side
    6–13
    Perigynium nerves upper side
    1–10
    Perigynium orientation
    • the perigynia are angled outwards
    • the perigynia are curved or bent downwards or backwards along the axis
    Perigynium puffy
    the perigynium is inflated (there is space between the perigynium and the achene)
    Perigynium shape
    • the perigynium body is orbicular (roughly circular, as wide as long)
    • the perigynium body is ovate (egg-shaped)
    Perigynium width
    1.5–3 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
    • brown
    • white or translucent
    Scale length
    1.2–2.4 mm
    Scale tip
    • the carpellate scale tip is acute (has a sharp point)
    • 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
    Staminate scale tip
    • 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 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
    1–1.9 mm
    Achene width
    1–1.7 mm
    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 mostly produced higher up on the plant
    Leaf blade cross-section
    The leaf blade is folded lengthwise, with one prominent midvien
    Leaf blade length to width ratio
    100–133
    Leaf blade texture
    the leaf blade is smooth and hairless, or rough and sandpapery
    Leaf blade width
    0.65–4.5 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
    Ligule length
    0.5–3.7 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
    0.65–4.5 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
  • Place

    Habitat
    wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • bogs
    • edges of wetlands
    • swamps
  • Stem, shoot, branch

    Plant height
    10–110 cm
    Relative stem height
    the main stem is taller than the leaves
    Spike internode length
    1.5–18 mm
    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

Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)

In New England

Distribution

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

Conservation status

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

Massachusetts
unranked (S-rank: SNR)

ssp. atlantica

Massachusetts
unranked (S-rank: SNR)
Vermont
extremely rare (S-rank: S1)

ssp. capillacea

Massachusetts
unranked (S-rank: SNR)
Vermont
extremely rare (S-rank: S1)

Subspecies and varieties

Carex atlantica var. atlantica Bailey is known from CT, MA, ME, NH, RI, VT.C. atlantica var. capillacea (Bailey) Cronq. is known from CT, MA, ME, NH, RI, VT.

From Flora Novae Angliae dichotomous key

170.  Carex atlantica Bailey N

prickly bog sedge.  170a. Carex incomperta Bickn.; C. stellulata Goodenough var. conferta Chapman;  170b. Carex atlantica Bailey ssp. capillacea (Bailey) Reznicek.; C. howei Mackenzie • CT, MA, ME, NH, RI, VT. Bogs, deciduous and coniferous swamps, wetland margins.

1a.  Widest leaf blades 1.6–4 (–4.5) mm wide; perigynia 2.3–3.8 mm long; inflorescences (1.5–) 1.8–5.5 cm tall … 170a. C. atlantica var. atlantica

1b.  Widest leaf blades (0.65–) 0.8–1.6 mm wide; perigynia 1.9–3 mm long; inflorescences 0.8–2 cm tall … 170b. C. atlantica var. capillacea (Bailey) Cronq.

Variety atlantica is known from CT, MA, ME, NH, RI, VT. Variety capillacea is known from CT, MA, ME, NH, RI, VT.

Native to North America?

Yes

Sometimes confused with

Carex echinata:
perigynia mostly 2.9-3.6 mm long with a beak mostly 0.95-2 mm long (vs. C. atlantica, with perigynia mostly 1.9-3 mm long with a beak 0.4-0.95 mm long).

Synonyms

  • Carex incomperta Bickn.
  • Carex stellulata Goodenough var. conferta Chapman

Family

Cyperaceae

Genus

Carex