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• Carex polymorpha

Carex polymorpha — variable sedge

Facts

With a restricted distribution on well-drained sandy soils from Maine to Virginia along the Eastern Seaboard, variable sedge is rare or endangered in most New England states, and has been a candidate for Federal listing, withdrawn after additional populations were found. Still, there are probably fewer than 45 populations in the world, about a third of them in New England. A few of these populaions are very large, covering many acres. It typically occurs in sandy, acidic soils with seasonal flooding or near wetlands.

Habitat

Anthropogenic (man-made or disturbed habitats), forest edges, woodlands

Characteristics

• Flowers

  Bumps on fruit

  the perigynium surface has papillae on it

  Inflorescence length

  60–190 mm

  Length of scale

  the scale is shorter than the perigynium

  Lowest spike length

  15–35 mm

  Lowest spike width

  7.5–11 mm

  Perigynium beak

  the perigynium has a beak

  Perigynium beak length

  0.6–1.8 mm

  Perigynium beak orientation

  • the beak of the perigynium is curved, or angled out from the perigynium
  • 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 divided at the top into two teeth

  Perigynium color

  • brown
  • yellow

  Perigynium cross-section

  the perigynium is relatively round in cross-section

  Perigynium hairs

  the perigynium has no hairs

  Perigynium length

  4.2–6.8 mm

  Perigynium nerve texture

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

  Perigynium orientation

  • the perigynia are angled outwards
  • 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 elliptic (widest near the middle and tapering at both ends)

  Perigynium width

  1.5–2.5 mm

  Perigynium winged

  the perigynium has no wings

  Pollen- and seed-producing spikes

  some of the spikes produce perigynia

  Pollen-producing spike length

  10–30 mm

  Pollen-producing spike number

  1–3

  Scale awn

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

  Scale awn texture

  NA

  Scale color

  • brown
  • purple to black

  Scale tip

  • the carpellate scale tip is obtuse (has a blunt point)
  • the carpellate scale tip is rounded to retuse (blunt or rounded, with a notch at the tip)

  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

  2.2–2.8 mm

  Achene width

  1.4–2.3 mm

  Style persistence

  the style falls off the mature achenes

• Growth form

  Rhizomes

  there are long rhizomes present

• Leaves

  Leaf arrangement

  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 length to width ratio

  16–75

  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

  2–10 mm

  Lowest bract sheath

  the lowest bract has a sheath longer than four millimeters

  Lowest leaf blade width

  2.5–6 mm

  Lowest leaf sheath texture

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

  stem leaf blade width

  2.5–6 mm

• Place

  Habitat

  terrestrial

  New England state

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

  Specific habitat

  • edges of forests
  • man-made or disturbed habitats
  • woodlands

• Stem, shoot, branch

  Plant height

  30–60 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 singly or a few together (they may form diffuse colonies)

Wetland status

Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae