- You are here:
- Simple Key
- Grass-like plants
- Sedges
- Carex swanii
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
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- stem 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
-
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 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)
- stem leaf blade width
- 1.5–3 mm
-
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
- widespread (S-rank: S5)
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.