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• Carex amphibola

Carex amphibola — eastern narrow-leaved sedge

Facts

Eastern narrow-leaved sedge has been used for horticultural purposes, as it forms dense tussocks and has attractive shiny green blades. This species is found in Massachusetts and Connecticut, where it occurs in rich upland and riparian forests.

Habitat

Floodplain (river or stream floodplains), forests

Characteristics

• Flowers

  Anther length

  2–2.8 mm

  Bumps on fruit

  there are no papillae on the perigynium surface

  Length of scale

  the scale is shorter than the perigynium

  Lowest spike length

  5–26 mm

  Lowest spike width

  4.6–9.8 mm

  Perigynium beak

  • the perigynium has a beak
  • the perigynium has no beak, or an extremely short beak

  Perigynium beak length

  0–0.2 mm

  Perigynium beak orientation

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

  Perigynium beak serrations

  the perigynium beak has no serrations

  Perigynium beak teeth

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

  Perigynium beak teeth length

  0 mm

  Perigynium color

  • brown
  • yellow

  Perigynium cross-section

  the perigynium is trigonous (triangular) in cross-section

  Perigynium hairs

  the perigynium has no hairs

  Perigynium length

  4.2–5.2 mm

  Perigynium nerve number

  52–64

  Perigynium nerve texture

  the nerves on the perigynium are flat or concave after drying

  Perigynium nerves lower side

  26–32

  Perigynium nerves upper side

  26–32

  Perigynium orientation

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

  Perigynium puffy

  the perigynium is inflated (there is space between the perigynium and the achene)

  Perigynium shape

  • the perigynium body is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
  • the perigynium body is oblong (rectangular but with rounded ends)
  • the perigynium body is ovate (egg-shaped)

  Perigynium width

  1.5–2.2 mm

  Perigynium winged

  the perigynium has no wings

  Pollen- and seed-producing spikes

  some of the spikes produce perigynia

  Pollen-producing spike length

  7–34 mm

  Pollen-producing spike number

  1

  Pollen-producing spike peduncle length

  1.6–37 mm

  Pollen-producing spike width

  1.1–2.7 mm

  Scale awn

  the carpellate scale has an awn on it

  Scale awn texture

  the carpellate scale awn has tiny teeth

  Scale color

  white or translucent

  Scale length

  3.7–8 mm

  Scale tip

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

  Spike on stalk

  the lowest spike on the plant has a peduncle

  Spike orientation

  the spikes are oriented vertically or pressed against the axis

  Spikes per stem

  2-15

  Stigma branching

  the stigmas have three branches

  Top spike

  the uppermost spike contains only staminate flowers

• Fruits or seeds

  Achene dimples

  the achene has no folds or dimples

  Achene length

  2.6–3.4 mm

  Achene width

  1.3–1.8 mm

  Style persistence

  the style falls off the mature achenes

• Leaves

  Leaf arrangement

  • the leaves are all produced from the base of the plant
  • the leaves are mostly produced higher up on the plant

  Leaf blade cross-section

  the leaf blade is flat or M-shaped, with two prominent side-veins

  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 is tinted pink, red or purple

  Leaf sheath dots

  there are no dots on 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

  1.8–12.9 mm

  Lowest bract sheath

  the lowest bract has a sheath longer than four millimeters

  Lowest leaf blade width

  3.7–7 mm

  Lowest leaf sheath texture

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

  stem leaf blade width

  3.7–7 mm

• Place

  Habitat

  • terrestrial
  • wetlands

  New England state

  • Connecticut
  • Massachusetts

  Specific habitat

  • forests
  • river or stream floodplains

• Stem, shoot, branch

  Plant height

  15–80 cm

  Relative stem height

  • the main stem is equal to or shorter than the leaves
  • the main stem is taller than the leaves

  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 in wetlands or non-wetlands. (Wetland indicator code: FAC)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae