Carex tenuiflora — sparse-flowered sedge
![Inflorescence: Carex tenuiflora. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/carex-tenuiflora-in-ahaines.jpg)
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Facts
Sparse-flowered sedge is a circumboreal species, but rare in New England, being mostly confined to white cedar (Thuja occidentalis) fens in Maine, New Hampshire and Vermont.
Habitat
Fens (calcium-rich wetlands)
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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enlargeCharacteristics
- Habitat
- wetlands
- New England state
-
- Maine
- New Hampshire
- Vermont
- Leaf blade width
- 0.5–2 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
- 3–3.5 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
- NA
-
Flowers
- Bumps on fruit
- the perigynium surface has papillae on it
- Inflorescence length
- 6–12 mm
- Length of scale
- the scale is nearly as long as, or longer than, the perigynium
- Lowest spike length
- 4–9 mm
- Lowest spike stalk length
- 0 mm
- Lowest spike width
- 3–6 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
- NA
- Perigynium beak teeth length
- 0 mm
- Perigynium color
- green
- 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
- 3–3.5 mm
- Perigynium nerve texture
- the nerves on the perigynium are raised, even after drying the perigynium
- Perigynium orientation
- the perigynia are oriented vertically or pressed against the axis or adjacent perigynia
- Perigynium puffy
- the achene is tightly enclosed by the perigynium
- Perigynium shape
- the perigynium body is oblong (rectangular but with rounded ends)
- Perigynium width
- 1.5–1.75 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
- white or translucent
- Scale tip
- 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
- 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
- 1.5–2 mm
- Achene width
- 1.25–1.5 mm
- Style persistence
- the style falls off the mature achenes
-
Growth form
- Rhizomes
- there are long rhizomes present
-
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
- the leaf blade is flat or M-shaped, with two prominent side-veins
- Leaf blade length to width ratio
- 75–100
- Leaf blade texture
- the leaf blade is smooth and hairless, or rough and sandpapery
- Leaf blade width
- 0.5–2 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
- 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 mm
- Lowest leaf sheath texture
- the leaf sheath feels smooth (it may have soft hairs)
-
Place
- Habitat
- wetlands
- New England state
-
- Maine
- New Hampshire
- Vermont
- Specific habitat
- fens (calcium-rich wetlands)
-
Stem, shoot, branch
- Plant height
- 10–50 cm
- Relative stem height
- 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
- absent
- Maine
- present
- Massachusetts
- absent
- 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.
- Maine
- uncommon (S-rank: S3), special concern (code: SC)
- Massachusetts
- unranked (S-rank: SNR)
- New Hampshire
- extremely rare (S-rank: S1), endangered (code: E)
- Vermont
- extremely rare (S-rank: S1)
From Flora Novae Angliae dichotomous key
72. Carex tenuiflora Wahlenb. NC
sparse-flowered sedge. ME, NH, VT; also reported from MA by Toivonen (2002), but specimens are unknown. Fens, usually in the shade of Thuja occidentalis.
72×73. Carex tenuiflora × Carex trisperma → Carex ×trichina Fern. is a rare sedge hybrid known from ME. Characteristics that distinguish this plant are its short-beaked perigynia and less congested inflorescence (compared with C. tenuiflora).