Eriophorum virginicum — tawny cottongrass, tawny cottonsedge

Characteristics

• Flowers

  Anther length

  0.7–1.5 mm

  Floral bristle color

  the bristles are pale brown to brown

  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

  4–5 mm

  Floral scale nerves

  • 2-5
  • 7 or more

  Floral scale shape

  • 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

  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
  • the inflorescence is on one or more stems with no branches

  Inflorescence crowding

  the inflorescence is crowded together in one tight cluster

  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

  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 triangular to terete (circular) in cross-section

  Fruit length

  2.5–4 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 300 mm

  Leaf blade width

  1.5–4 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

  40–120 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

  0.6–1 mm

Wetland status

Occurs only in wetlands. (Wetland indicator code: OBL)

In New England

From Flora Novae Angliae dichotomous key