Carex trisperma — three-seeded sedge

Characteristics

• Flowers

  Bumps on fruit

  • the perigynium surface has papillae on it
  • there are no papillae on the perigynium surface

  Inflorescence length

  14–55 mm

  Length of scale

  • the scale is nearly as long as, or longer than, the perigynium
  • the scale is shorter than the perigynium

  Lowest spike stalk length

  0 mm

  Perigynium beak

  the perigynium has a beak

  Perigynium beak length

  0–0.5 mm

  Perigynium beak orientation

  the beak of the perigynium is straight, and in line with the perigynium

  Perigynium beak serrations

  • the perigynium beak has no serrations
  • the perigynium beak has tiny serrations along the edges

  Perigynium beak teeth

  • the perigynium beak is divided at the top into two teeth
  • the perigynium beak is not divided at the tip into two teeth, or the teeth are very tiny

  Perigynium beak teeth length

  At least 0 mm

  Perigynium color

  • brown
  • green

  Perigynium cross-section

  the perigynium is planoconvex (flat on one surface and rounded on the other) in cross-section

  Perigynium hairs

  the perigynium has no hairs

  Perigynium length

  2.5–3.7 mm

  Perigynium nerve texture

  the nerves on the perigynium are raised, even after drying the perigynium

  Perigynium orientation

  the perigynia are oriented vertically or pressed against the axis or adjacent perigynia

  Perigynium puffy

  the achene is tightly enclosed by the perigynium

  Perigynium shape

  • the perigynium body is elliptic (widest near the middle and tapering at both ends)
  • the perigynium body is ovate (egg-shaped)

  Perigynium width

  1.5–2 mm

  Perigynium winged

  the perigynium has no wings

  Pollen- and seed-producing spikes

  some of the spikes produce perigynia

  Pollen-producing spike length

  0 mm

  Pollen-producing spike number

  0

  Pollen-producing spike peduncle length

  0 mm

  Pollen-producing spike width

  0 mm

  Scale awn

  The carpellate scale does not have an awn (it may have a short point)

  Scale awn texture

  NA

  Scale color

  white or translucent

  Scale tip

  the carpellate scale tip is acute (has a sharp point)

  Spike on stalk

  the lowest spike on the plant is not borne on a peduncle

  Spike orientation

  the spikes are bent downwards or droop downwards

  Spikes per stem

  2-15

  Staminate scale tip

  the staminate scale tip is acuminate (tapered to a narrow point)

  Stigma branching

  the stigmas have two branches

  Top spike

  the uppermost spike contains both staminate and carpellate flowers, with the staminate flowers located below the carpellate flowers

• Fruits or seeds

  Achene dimples

  the achene has no folds or dimples

  Achene length

  1.75–2 mm

  Achene width

  1.25–1.5 mm

  Style persistence

  the style falls off the mature achenes

• Growth form

  Rhizomes

  there are long rhizomes present

• Leaves

  Leaf arrangement

  the leaves are all produced from the base of the plant

  Leaf blade cross-section

  • The leaf blade is folded lengthwise, with one prominent midvien
  • the leaf blade is flat or M-shaped, with two prominent side-veins

  Leaf blade length to width ratio

  100–200

  Leaf blade texture

  the leaf blade is smooth and hairless, or rough and sandpapery

  Leaf bumps

  the upper surface of the leaf blade does not have papillae

  Leaf sheath bumps

  there are no papillae at the top edge of the leaf sheath

  Leaf sheath color

  the leaf sheath has no pink, red or purple tinting

  Leaf sheath dots

  there are white dots on the green tissues of the leaf sheathes

  Leaf sheath folds

  there are no corrugations on the leaf sheath

  Leaf sheath texture

  the leaf sheath feels smooth, and has no hairs

  Ligule length

  0.5–1.9 mm

  Lowest bract sheath

  the lowest bract has no sheath (or a very short sheath up to four millimeters in length)

  Lowest leaf blade width

  0.8–1.9 mm

  Lowest leaf sheath texture

  the leaf sheath feels smooth (it may have soft hairs)

  stem leaf blade width

  0.8–1.9 mm

• Place

  Habitat

  wetlands

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont

  Specific habitat

  • bogs
  • fens
  • forests
  • swamps

• Stem, shoot, branch

  Plant height

  20–70 cm

  Relative stem height

  the main stem is taller than the leaves

  Spike internode length

  20–40 mm

  Stem cross-section

  the main stem is roughly triangular in cross-section

  Stem spacing

  the stems grow close together in compact clusters or tufts

Wetland status

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

In New England

From Flora Novae Angliae dichotomous key