Carex oligosperma — few-seeded sedge
![Achenes: Carex oligosperma. ~ By Jill Weber. ~ Copyright © 2024 Jill Weber. ~ jillweber03[at]gmail.com](https://newfs.s3.amazonaws.com:443/taxon-images-1000s1000/Cyperaceae/carex-oligosperma-ac-jweber.jpg)
![Inflorescence: Carex oligosperma. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com:443/taxon-images-1000s1000/Cyperaceae/carex-oligosperma-in-ahaines.jpg)
![Leaves: Carex oligosperma. ~ By Jill Weber. ~ Copyright © 2024 Jill Weber. ~ jillweber03[at]gmail.com](https://newfs.s3.amazonaws.com:443/taxon-images-1000s1000/Cyperaceae/carex-oligosperma-le-jweber.jpg)
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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.
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enlargeFacts
Few-seeded sedge is a sedge of bogs, acidic fens and wet meadows. The Iroquois made a decoction of this plant that they used as an emetic before running or playing lacrosse.
Habitat
Bogs, fens, meadows and fields
Characteristics
- Habitat
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- stem leaf blade width
- 0.5–2.5 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 has a peduncle
- the lowest spike on the plant is not borne on a peduncle
- Top spike
- the uppermost spike contains only staminate flowers
- Perigynium hairs
- the perigynium has no hairs
- Perigynium length
- 4–6.7 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
-
Flowers
- Bumps on fruit
- there are no papillae on the perigynium surface
- Inflorescence length
- 30–200 mm
- Length of scale
- the scale is shorter than the perigynium
- Lowest spike length
- 10–20 mm
- Lowest spike stalk length
- At least 0 mm
- Perigynium beak
- the perigynium has a beak
- Perigynium beak length
- 0.3–0.9 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
- Up to 0.3 mm
- Perigynium color
-
- brown
- 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
- 4–6.7 mm
- Perigynium nerve number
- 7–15
- Perigynium nerve texture
- the nerves on the perigynium are raised, even after drying the perigynium
- Perigynium nerves lower side
- 3–7
- Perigynium nerves upper side
- 3–7
- 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
- 2.5–3.4 mm
- Perigynium winged
- the perigynium has no wings
- Pollen- and seed-producing spikes
- some of the spikes produce perigynia
- Pollen-producing spike number
- 1–2
- 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
- 3.2–5.6 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 has a peduncle
- 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)
- 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
- Achene length
- 2–3 mm
- 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 folded lengthwise, with one prominent midvien
- 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
- 0.5–2.5 mm
- Lowest leaf sheath texture
- the leaf sheath feels smooth (it may have soft hairs)
- stem leaf blade width
- 0.5–2.5 mm
-
Place
- Habitat
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Specific habitat
-
- bogs
- fens
- meadows or fields
-
Stem, shoot, branch
- Plant height
- 30–90 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
Occurs only in wetlands. (Wetland indicator code: OBL)
New England distribution and conservation status
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- absent
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Connecticut
- historical (S-rank: SH), special concern, extirpated (code: SC*)
- Maine
- unranked (S-rank: SNR)
- Massachusetts
- extremely rare (S-rank: S1), endangered (code: E)
- Vermont
- rare to uncommon (S-rank: S2S3)
Native to North America?
Yes
Sometimes confused with
- Carex saxatilis:
- flowers with 2 stigmas, achenes biconvex, and perigynia obscurely veined (vs. C. oligosperma, with carpellate flowers with 3 stigmas, achenes triangular in cross-section, and perigynia distinctly veined).
- Carex vesicaria:
- perigynium beak 1.1-2.6 mm long, with two evident, terminal teeth, and leaf blades flat to V-shaped, with plane margins, 1.8-6.5 mm wide (vs. C. oligosperma, with the perigynium beak 0.3–0.9 mm long, obscurely bidentate at tip, and leaf blades filiform, with involute margins, 0.5–2.5 mm wide).
Family
Genus
From the dichotomous key of Flora Novae Angliae
183. Carex oligosperma Michx. N
few-seeded sedge. CT, MA, ME, NH, VT. Bogs, acidic fens, and wet meadows.