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)
Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.
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
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.
enlargeCharacteristics
- Habitat
- wetlands
- New England state
-
- Maine
- New Hampshire
- Vermont
- stem 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 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)
- stem leaf blade width
- 0.5–2 mm
-
Place
- Habitat
- wetlands
- New England state
-
- Maine
- New Hampshire
- Vermont
- Specific habitat
- fens
-
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).
Native to North America?
Yes
Sometimes confused with
- Carex leptalea:
- reproductive stems with a single spike, androgynous, and flowers with 3 styles (vs. C. tenuiflora, with reproductive stems with 2-4 spikes crowded together, at least the terminal one gynecandrous, and flowers with 2 styles).