Eriophorum gracile — slender cottongrass, slender cottonsedge
![Leaves and auricles: Eriophorum gracile. ~ By Dean Wm. Taylor. ~ Copyright © 2024 Dean Wm. Taylor. ~ deanwmtaylor[at]gmail.com ~ CalPhotos - calphotos.berkeley.edu/flora/](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/eriophorum-gracile-la-dtaylor.jpg)
![Inflorescences: Eriophorum gracile. ~ By Bud Kovalchik. ~ Copyright © 2024 Bud Kovalchik. ~ bkovalchik7[at]gmail.com ~ U. of Washington - WTU - Herbarium - biology.burke.washington.edu/herbarium/imagecollection.php](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/eriophorum-gracile-in-bkovalchik.jpg)
![Plant form: Eriophorum gracile. ~ By Bud Kovalchik. ~ Copyright © 2024 Bud Kovalchik. ~ bkovalchik7[at]gmail.com ~ U. of Washington - WTU - Herbarium - biology.burke.washington.edu/herbarium/imagecollection.php](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/eriophorum-gracile-ha-bkovalchik.jpg)
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Facts
Slender cottonsedge is a circumboreal species that inhabits bogs, fens and meadows in all New England states; it is listed as threatened in Massachusetts and Rhode Island. This is a slender cottonsedge, growing 8 to 24 inches tall, with very narrow leaf blades. One leaf (bract) subtends the small, white, cottony spikelet -- it is shorter than the inflorescence and sometimes black at its base. This characteristic helps distinguish this species from other cottonsedges. Because most of the wetlands this species inhabits get their water solely from groundwater, slender cottonsedge can be harmed by alterations to the hydrology.
Habitat
Bogs, fens, meadows and fields
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
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Stem shape in cross-section
-
- the stem is roughly triangular in cross-section
- the stem is round or oval in cross-section
- Leaf blade width
- 1–2 mm
- Leaf blade cross-section
- the leaf blade is triangular in cross-section
- Inflorescence position
- the inflorescence is at the tip of the plant
- Inflorescence branching
-
- the inflorescence is branched
- the inflorescence is on one or more stems with no branches
- Fruit type (general)
-
- the fruit is like a seed, and surrounded by hairs
- the fruit is like a seed, and surrounded by scales
- Fruit length
- 1.5–3 mm
- Leaf position on plant
- some leaf attachment points are above the midpoint of the stem
- Perianth composition
- there are bristles attached at the base of the achene
- Fruit cross-section
- the fruit is triangular to terete (circular) in cross-section
-
Flowers
- Anther length
- 1–2.5 mm
- Floral bristle color
- the bristles are white
- Floral bristle number
- 8 or more
- Floral bristle relative length
- the bristles are longer than the achene
- Floral bristles
- the bristles are straight or slightly curved
- Floral scale hairs
- there are no hairs on the floral scales
- Floral scale length
- 3–4 mm
- Floral scale nerves
-
- 2-5
- 7 or more
- Floral scale shape
- the floral scales are ovate (roughly egg-shaped)
- Floral scale translucent
- the floral scales are opaque
- Inflorescence bract angle
- the bracts are vertical or angled only slightly outwards
- Inflorescence bract number
- there is just one bract on the inflorescence
- Inflorescence bract position (Sparganium)
- NA
- Inflorescence bracts
- there is only one bract, and it looks like a continuation of the stem
- Inflorescence branching
-
- the inflorescence is branched
- the inflorescence is on one or more stems with no branches
- Inflorescence crowding
- the inflorescence is at least somewhat spread out, with at least one branch coming from the main stem
- Inflorescence position
- the inflorescence is at the tip of the plant
- Inflorescence shape
- the aggregations within the inflorescence are roughly circular (not flattened) in cross-section
- Inflorescence type
-
- there are two or more flowers, spikes or flower clusters on a branched inflorescence
- there is one spike or raceme at the tip of the stem
- Perianth composition
- there are bristles attached at the base of the achene
- Stamen number
-
- 1
- 2
- 3
- Stigma number
- 3
- Style division
- the top two thirds of the style is divided
- floral bristle barbs
- the bristles do not have barbs on them
-
Fruits or seeds
- Achene beak length
- 0 mm
- Achene tubercle relative width
- NA
- Achene tubercle width
- 0 mm
- Capsule relative length
- NA
- Fruit cross-section
- the fruit is triangular to terete (circular) in cross-section
- Fruit length
- 1.5–3 mm
- Fruit type (general)
-
- the fruit is like a seed, and surrounded by hairs
- the fruit is like a seed, and surrounded by scales
- Fruit type (specific)
- the fruit is an achene (dry, seed-like fruit) without a tubercle (a swelling or projection, usually of a different color or texture)
- Locules in capsule
- NA
- Seed length
- 0 mm
- Seed tail relative length
- 0 mm
- Seed tails
- NA
- Tubercle height
- 0 mm
-
Growth form
- Lifespan
- the plant lives more than two years
- Underground organs
- the plant has a rhizome (a horizontal underground stem with roots growing from it)
-
Leaves
- Auricle length
- 0 mm
- Auricle texture
- NA
- Auricles
- there are no auricles on the leaf sheath
- Leaf blade cross-section
- the leaf blade is triangular in cross-section
- Leaf blade length
- 10–40 mm
- Leaf blade width
- 1–2 mm
- Leaf form
- all the leaves hold their form out of water
- Leaf position on plant
- some leaf attachment points are above the midpoint of the stem
- Leaf septa
- the leaf blades do not have transverse septa
- Leaf sheath hairs
- the leaf sheathes are without hairs
- Pedicel length (Typha)
- 0 mm
- Stem leaf blade ligules
- the plant has ligules at the leaf blade bases
- Stem leaf blades
- there are fully-developed leaves with leaf blades on the main stem
-
Place
- Habitat
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- bogs
- fens
- meadows or fields
-
Stem, shoot, branch
- Plant height
- 20–60 cm
- Stem shape in cross-section
-
- the stem is roughly triangular in cross-section
- the stem is round or oval in cross-section
- Stem texture near tip
- the stem feels smooth near the tip
- Stem thickness at midpoint
- 0.5–0.8 mm
Wetland status
Occurs only in wetlands. (Wetland indicator code: OBL)
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
- rare (S-rank: S2), threatened (code: T)
- Rhode Island
- extremely rare (S-rank: S1), state threatened (code: ST)
- Vermont
- extremely rare (S-rank: S1)
From Flora Novae Angliae dichotomous key
2. Eriophorum gracile W.D.J. Koch N
slender cottonsedge. CT, MA, ME, NH, RI, VT. Bogs, acidic fens, meadows.
Native to North America?
Yes
Sometimes confused with
- Eriophorum tenellum:
- uppermost leaf blade 3–25 cm long, as long or longer than its associated sheath, and apical portion of stem and peduncles scabrous (vs. E. gracile, with the uppermost leaf blade 1–4 cm long, shorter than its sheath, and apical portion of stems and peduncles not scabrous).