Eriophorum gracile W.D.J. Koch

slender cottongrass, slender cottonsedge

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New England Distribution

Adapted from BONAP data

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North America Distribution

Adapted from BONAP data

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Facts About

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

Characteristics

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
Show All Characteristics
  • 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)

New England Distribution and Conservation Status

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)

var. gracile

Massachusetts
unranked (S-rank: SNR)

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).

Family

Cyperaceae

Genus

Eriophorum

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Information from Dichotomous Key of Flora Novae Angliae

2.  Eriophorum gracile W.D.J. Koch N

slender cottonsedge. CT, MA, ME, NH, RI, VT. Bogs, acidic fens, meadows.