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Carex retrorsa — retrorse sedge

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Facts

Retrorse sedge inhabits gets its name from the fact that the lower perigynia on the spike point roughly downward along the stem. It inhabits stream and lake shores, swamps, marshes and grassy meadows throughout New England.

Habitat

Marshes, meadows and fields, shores of rivers or lakes, swamps

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
stem leaf blade width
3–10 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
  • 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 carpellate flowers located below, or intermixed with, the staminate flowers
  • the uppermost spike contains only staminate flowers
Perigynium hairs
the perigynium has no hairs
Perigynium length
6–10 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 divided at the top into two teeth
Show all characteristics

  • Flowers

    Bumps on fruit
    there are no papillae on the perigynium surface
    Inflorescence length
    30–350 mm
    Length of scale
    the scale is shorter than the perigynium
    Lowest spike length
    15–50 mm
    Lowest spike stalk length
    At least 0 mm
    Lowest spike width
    15–20 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    2.1–4.5 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
    0.3–1.1 mm
    Perigynium color
    • green
    • tan
    Perigynium cross-section
    • the perigynium is relatively round in cross-section
    • the perigynium is trigonous (triangular) in cross-section
    Perigynium hairs
    the perigynium has no hairs
    Perigynium length
    6–10 mm
    Perigynium nerve number
    6–13
    Perigynium nerve texture
    the nerves on the perigynium are raised, even after drying the perigynium
    Perigynium nerves lower side
    3–6
    Perigynium nerves upper side
    3–6
    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 ovate (egg-shaped)
    Perigynium width
    1.6–3.4 mm
    Perigynium winged
    the perigynium has no wings
    Pollen- and seed-producing spikes
    some of the spikes produce perigynia
    Pollen-producing spike number
    1–3
    Scale awn
    The carpellate scale does not have an awn (it may have a short point)
    Scale awn texture
    NA
    Scale color
    • brown
    • green
    Scale length
    2.4–4.5 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
    • the lowest spike on the plant is not borne on a peduncle
    Spike orientation
    • the spikes are angled outwards, or arched over
    • 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 both staminate and carpellate flowers, with the carpellate flowers located below, or intermixed with, the staminate flowers
    • the uppermost spike contains only staminate flowers

  • Fruits or seeds

    Achene dimples
    the achene has no folds or dimples
    Achene length
    2 mm
    Style persistence
    the style stays on 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 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
    Lowest bract sheath
    the lowest bract has no sheath (or a very short sheath up to four millimeters in length)
    Lowest leaf blade width
    3–10 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    3–10 mm

  • Place

    Habitat
    wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • marshes
    • meadows or fields
    • shores of rivers or lakes
    • swamps

  • Stem, shoot, branch

    Plant height
    10–105 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
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
rare to uncommon (S-rank: S2S3)
New Hampshire
unrankable (S-rank: SU), Ind (code: Ind)

From Flora Novae Angliae dichotomous key

185.  Carex retrorsa Schwein. N

retrorse sedge. CT, MA, ME, NH, RI, VT. Stream shores, lake shores, marshes, graminoid meadows, openings in swamps.

182×185. Carex lurida × Carex retrorsa → 182 × 185. Carex ×hartii Dewey is a rare sedge hybrid known from MA, ME, NH, VT. It resembles C. retrorsaits in that its spikes have wide-spreading to retrorse perigynia and the very long lowermost bracts that long-exceed the inflorescences. However, the hybrid has carpellate scales that are long-acuminate to awned at the apex and distal stems that are scabrous on the margins (vs. carpellate scales that are acuminate and distal stems that are smooth on the margins).

Native to North America?

Yes

Sometimes confused with

Carex utriculata:
bract of lowermost carpellate spike with a blade up to 2.5 times as long as the inflorescence and staminate spikes numbering 2-5 per inflorescence, well elevated above the uppermost carpellate spike (vs. C. retrorsa, with the bract of lowermost carpellate spike with a blade (2.5–) 3–9 times as long as the inflorescence and staminate spike usually solitary, barely elevated above the uppermost carpellate spike).

Family

Cyperaceae

Genus

Carex