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• Carex backii

Carex backii — Back's sedge

Facts

The lowest carpellate scales of Back's sedge are much longer than the perigynia, and bright green. The uppermost flowering spike is androgynous, with two or three staminate flowers, the rest being carpellate. This species is rare in southern New England.

Habitat

Cliffs, balds, or ledges, forests, woodlands

Characteristics

• Flowers

  Anther length

  0.9–1.3 mm

  Bumps on fruit

  there are no papillae on the perigynium surface

  Length of scale

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

  Perigynium beak

  the perigynium has a beak

  Perigynium beak length

  1.9–2.9 mm

  Perigynium beak orientation

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

  Perigynium beak serrations

  the perigynium beak has tiny serrations along the edges

  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

  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

  4.8–6.6 mm

  Perigynium nerve number

  At least 0

  Perigynium nerve texture

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

  Perigynium nerves lower side

  At least 0

  Perigynium nerves upper side

  At least 0

  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)
  • the perigynium body is ovate (egg-shaped)

  Perigynium width

  1.9–3.2 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

  green

  Scale length

  15–70 mm

  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 oriented vertically or pressed against the axis

  Spikes per stem

  • 1
  • 2-15

  Staminate scale tip

  the staminate scale tip is obtuse (has a blunt point)

  Stigma branching

  the stigmas have three branches

  Top spike

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

• Fruits or seeds

  Achene dimples

  the achene has no folds or dimples

  Achene length

  2.5–3.2 mm

  Achene width

  1.6–2.3 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 all produced from the base of the plant

  Leaf blade cross-section

  The leaf blade is folded lengthwise, with one prominent midvien

  Leaf blade texture

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

  Leaf blade width

  1.3–5.4 mm

  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 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

  Lowest bract sheath

  NA

  Lowest leaf blade width

  1.3–5.4 mm

  Lowest leaf sheath texture

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

• Place

  Habitat

  terrestrial

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Vermont

  Specific habitat

  • cliffs, balds, or ledges
  • forests
  • woodlands

• Stem, shoot, branch

  Plant height

  1.4–25 cm

  Relative stem height

  the main stem is equal to or shorter than the leaves

  Spike internode length

  At least 0 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

Not classified

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae