• You are here:
• Dichotomous Key
• Cyperaceae
• Carex
• Carex Group 6
• Section Hymenochlaenae
• Carex castanea

Carex castanea — chestnut sedge

Facts

Chestnut sedge is rare in New England, where it is found on calcareous river shores, lake shores and meadows.

Habitat

Fens, floodplain (river or stream floodplains), meadows and fields, shores of rivers or lakes

Characteristics

• Flowers

  Bumps on fruit

  there are no papillae on the perigynium surface

  Distance between perigynia

  1 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 length

  8–25 mm

  Lowest spike stalk length

  10–20 mm

  Lowest spike width

  4–5 mm

  Perigynium beak

  the perigynium has a beak

  Perigynium beak length

  0.5–1.5 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

  Perigynium beak teeth

  the perigynium beak is divided at the top into two teeth

  Perigynium beak teeth length

  0.5 mm

  Perigynium color

  green

  Perigynium cross-section

  • the perigynium is relatively round in cross-section
  • the perigynium is trigonous (triangular) in cross-section

  Perigynium hairs

  the perigynium has no hairs

  Perigynium length

  2.5–5 mm

  Perigynium nerve number

  14–18

  Perigynium nerve texture

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

  Perigynium nerves lower side

  5–7

  Perigynium nerves upper side

  5–7

  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 elliptic (widest near the middle and tapering at both ends)

  Perigynium width

  1.3–2.5 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

  Pollen-producing spike peduncle length

  0–5 mm

  Pollen-producing spike width

  1.4–4 mm

  Scale awn

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

  Scale awn texture

  • the carpellate scale awn does not have teeth (it may or may not have hairs)
  • the carpellate scale awn has tiny teeth

  Scale color

  • green
  • red-brown
  • white or translucent

  Scale tip

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

  Spike on stalk

  the lowest spike on the plant has a peduncle

  Spike orientation

  • the spikes are angled outwards, or arched over
  • the spikes are bent downwards or droop downwards
  • 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

  1.5–2 mm

  Achene width

  1–1.5 mm

  Style persistence

  the style falls off the mature achenes

• Growth form

  Rhizomes

  there are no rhizomes, or the rhizomes are very short

• 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 texture

  the leaf blade is hairy

  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 red dots on the translucent tissues of the leaf sheathes

  Leaf sheath folds

  there are no corrugations on the leaf sheath

  Leaf sheath texture

  the leaf sheath feels rough, or has hairs

  Lowest bract sheath

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

  Lowest leaf blade width

  2.5–9 mm

  Lowest leaf sheath texture

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

  stem leaf blade width

  2.5–9 mm

• Place

  Habitat

  • terrestrial
  • wetlands

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Vermont

  Specific habitat

  • fens
  • meadows or fields
  • river or stream floodplains
  • shores of rivers or lakes

• Stem, shoot, branch

  Plant height

  40–90 cm

  Relative stem height

  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

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

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae