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• Cyperaceae
• Eriophorum
• Eriophorum gracile

Eriophorum gracile — slender cottongrass, slender cottonsedge

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 (calcium-rich wetlands), meadows and fields

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 (calcium-rich wetlands)
  • 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

From the dichotomous key of Flora Novae Angliae