Your help is appreciated. We depend on donations to help keep this site free and up to date for you. Can you please help us?

Donate

Native Plant Trust: Go Botany Discover thousands of New England plants

Carex swanii — Swan's sedge

Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.

Facts

This species was named for New England botanist Charles Walter Swan (1838-1921). It closely resembles ribbed sedge (Carex virescens).

Habitat

Forests, woodlands

New England distribution

Adapted from BONAP data

Found this plant? Take a photo and post a sighting.

North America distribution

Adapted from BONAP data

enlarge

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Leaf blade width
1.5–3 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 both staminate and carpellate flowers, with the staminate flowers located below the carpellate flowers
Perigynium hairs
the perigynium is hairy
Perigynium length
1.7–2.4 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 not divided at the tip into two teeth, or the teeth are very tiny
Show all characteristics
  • Flowers

    Anther length
    0.7–1.6 mm
    Bumps on fruit
    there are no papillae on the perigynium surface
    Length of scale
    the scale is nearly as long as, or longer than, the perigynium
    Lowest spike length
    5–19 mm
    Lowest spike width
    2–4 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
    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 trigonous (triangular) in cross-section
    Perigynium hairs
    the perigynium is hairy
    Perigynium length
    1.7–2.4 mm
    Perigynium nerve number
    5–13
    Perigynium nerve texture
    the nerves on the perigynium are raised, even after drying the perigynium
    Perigynium nerves lower side
    2–6
    Perigynium nerves upper side
    2–6
    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 obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
    • the perigynium body is orbicular (roughly circular, as wide as long)
    Perigynium width
    1–1.5 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 has an awn on it
    Scale awn texture
    the carpellate scale awn does not have teeth (it may or may not have hairs)
    Scale color
    • green
    • white or translucent
    Scale length
    1.3–2.4 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
    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 obtuse (has a blunt point)
    Stigma branching
    the stigmas have three 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
    1.4–1.8 mm
    Achene width
    0.8–1.1 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 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 hairy
    Leaf blade width
    1.5–3 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 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
    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 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • forests
    • woodlands
  • Stem, shoot, branch

    Plant height
    15–75 cm
    Relative stem height
    the main stem is equal to or shorter 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

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

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)

From Flora Novae Angliae dichotomous key

160.  Carex swanii (Fern.) Mackenzie N

Swan’s sedge. Carex virescens Muhl. ex Willd. var. swanii Fern. • CT, MA, ME, NH, RI, VT. 
Dry-mesic to mesic forests and woodlands.

Native to North America?

Yes

Sometimes confused with

Carex virescens:
uppermost spike mostly 20-35 mm long and loosely flowered near the base (vs. C. swanii, with the uppermost spike mostly 11-20 mm long and densely flowered throughout).

Synonyms

  • Carex virescens var. swanii Fern.

Family

Cyperaceae

Genus

Carex