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Eriophorum angustifolium — tall cottongrass, tall cottonsedge

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Facts

Tall cottonsedge is found across the northern United States and Canada. In New England it occurs in Maine and New Hampshire in peaty soils, shorelines and temporary pools. Native Americans of Alaska used the roots, stems and seeds for food, and the stems for weaving mats.

Habitat

Bogs, fens (calcium-rich wetlands), shores of rivers or lakes, wetland margins (edges of wetlands)

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
  • terrestrial
  • wetlands
New England state
  • Maine
  • New Hampshire
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
1.5–8 mm
Leaf blade cross-section
the leaf blade is flat or rolled in at the edges
Inflorescence position
the inflorescence is at the tip of the plant
Inflorescence branching
the inflorescence is branched
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
2–5 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
    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
    5–10 mm
    Floral scale nerves
    1
    Floral scale shape
    • the floral scales are lanceolate (widest below the middle, and tapering at both ends)
    • the floral scales are ovate (roughly egg-shaped)
    Floral scale translucent
    the floral scales are translucent
    Flower number per cluster
    • 5-20
    • more than 20
    Inflorescence bract angle
    the bracts are vertical or angled only slightly outwards
    Inflorescence bract number
    there are two to five bracts per inflorescence
    Inflorescence bract position (Sparganium)
    NA
    Inflorescence bracts
    there are at least two bracts, and they are either flat or folded or rolled in at the edges
    Inflorescence branching
    the inflorescence is branched
    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
    Perianth composition
    there are bristles attached at the base of the achene
    Stamen number
    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
    2–5 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 flat or rolled in at the edges
    Leaf blade length
    Up to 400 mm
    Leaf blade width
    1.5–8 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
    • terrestrial
    • wetlands
    New England state
    • Maine
    • New Hampshire
    Specific habitat
    • bogs
    • edges of wetlands
    • fens (calcium-rich wetlands)
    • shores of rivers or lakes
  • Stem, shoot, branch

    Plant height
    20–100 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 edges of the stem feel rough near the tip
    Stem thickness at midpoint
    0.8–1.2 mm

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
absent

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
unranked (S-rank: SNR)
New Hampshire
extremely rare (S-rank: S1), endangered (code: E)

var. coloratum

Massachusetts
unranked (S-rank: SNR)

Subspecies and varieties

Our subspecies is Eriophorum angustifolium Honckeny ssp. angustifolium.

From Flora Novae Angliae dichotomous key

1.  Eriophorum angustifolium Honckeny ssp. angustifolium N

tall cottonsedge. ME, NH; also reported from VT by Hultén and Fries (1986), but specimens are unknown. Peatlands, shorelines, peaty soils around temporary pools.

Native to North America?

Yes

Sometimes confused with

Eriophorum viridicarinatum:
summit of leaf sheath not darkended and midrib of floral scales conspicuous near apex (vs. E. angustifolium, with the summit of leaf sheath darkened and midrib of floral scales inconspicuous near apex).

Family

Cyperaceae

Genus

Eriophorum