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Scirpus cyperinus — common woolsedge, woolgrass

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Facts

Common woolsedge is a late-ripening species whose name derives from the perianth bristles that give the inflorescence a fuzzy or wooly appearance. The Ojibwa used common woodsedge for weaving bags and mats, and the Potawatomi used the fruiting heads to stuff pillows.

Habitat

Marshes, meadows and fields, 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
  • aquatic
  • 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
3–10 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
0.6–0.9 mm
Leaf position on plant
  • some leaf attachment points are above the midpoint of the stem
  • the attachment points of all the leaves are at or near the base of the plant
Perianth composition
there are bristles attached at the base of the achene
Fruit cross-section
  • the fruit is lenticular (lens-shaped) in cross-section
  • the fruit is triangular to terete (circular) in cross-section
Show all characteristics

  • Flowers

    Floral bristle number
    5-7
    Floral bristle relative length
    the bristles are longer than the achene
    Floral bristles
    the bristles are strongly bent or curled
    Floral scale hairs
    there are no hairs on the floral scales
    Floral scale length
    1.1–2.2 mm
    Floral scale nerves
    1
    Floral scale shape
    • the floral scales are elliptic (widest in the middle and tapering toward each end)
    • the floral scales are oblong (rectangular but with rounded ends)
    • the floral scales are ovate (roughly egg-shaped)
    Floral scale translucent
    the floral scales are opaque
    Inflorescence bract angle
    the bracts are angled outwards near horizontal or reflexed downwards
    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
    • 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 tubercle relative width
    NA
    Achene tubercle width
    0 mm
    Capsule relative length
    NA
    Fruit cross-section
    • the fruit is lenticular (lens-shaped) in cross-section
    • the fruit is triangular to terete (circular) in cross-section
    Fruit length
    0.6–0.9 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
    220–800 mm
    Leaf blade width
    3–10 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
    • the attachment points of all the leaves are at or near the base of the plant
    Leaf septa
    • the leaf blades do not have transverse septa
    • the leaf blades 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
    • aquatic
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • edges of wetlands
    • marshes
    • meadows or fields
    • shores of rivers or lakes

  • Stem, shoot, branch

    Plant height
    75–200 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

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.

Maine
unranked (S-rank: SNR)
Massachusetts
widespread (S-rank: S5)

From Flora Novae Angliae dichotomous key

4.  Scirpus cyperinus (L.) Kunth N

common woolsedge. Scirpus cyperinus (L.) Kunth var. pelius Fern.; S. cyperinus (L.) Kunth 
var. rubricosus Fern. • CT, MA, ME, NH, RI, VT. Wet fields, lake borders, graminoid marshes, temporary pools.

2×4. Scirpus atrocinctus × Scirpus cyperinus → This woolsedge nothospecies somewhat resembles Scirpus atrocinctus, except that it possesses a very different phenology, especially in regard to fruit maturation (often in late July and early August).

Native to North America?

Yes

Sometimes confused with

Scirpus pedicellatus:
spikelets mostly or entirely solitary, sessile or pedicellate, floral scales 1.4–1.8 mm long, and achenes maturing in July (vs. S. cyperinus, with spikelets mostly or all in glomerules of 2 or more, floral scales mostly shorter than 1.5 mm, and achenes maturing in August and September).

Synonyms

  • Scirpus cyperinus var. pelius Fern.
  • Scirpus cyperinus var. rubricosus Fern.

Family

Cyperaceae

Genus

Scirpus