Your help is appreciated. We depend on donations to help keep this site free and up to date for you. Can you please help us?

Donate

Native Plant Trust: Go Botany Discover thousands of New England plants

Carex atratiformis — scabrous black sedge

Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.

Facts

Found only in the northern portions of Vermont, New Hampshire and Maine, scabrous black sedge is so named because the mature perigynia are dark brown to dark red-brown, and the spikes are borne on slender stalks that are scabrous just under the inflorescence.

Habitat

Alpine or subalpine zones, cliffs, balds, or ledges, shores of rivers or lakes

New England distribution

Adapted from BONAP data

Found this plant? Take a photo and post a sighting.

North America distribution

Adapted from BONAP data

enlarge

Characteristics

Habitat
  • terrestrial
  • wetlands
New England state
  • Maine
  • New Hampshire
  • Vermont
stem leaf blade width
2.5–5 mm
Lowest bract sheath
the lowest bract has no sheath (or a very short sheath up to four millimeters in length)
Spike on stalk
the lowest spike on the plant has a peduncle
Top spike
the uppermost spike contains both staminate and carpellate flowers, with the staminate flowers located below the carpellate flowers
Perigynium hairs
the perigynium has no hairs
Perigynium length
2.5–3 mm
Leaf sheath color
the leaf sheath is tinted pink, red or purple
Leaf blade texture
the leaf blade is smooth and hairless, or rough and sandpapery
Perigynium beak teeth
the perigynium beak is divided at the top into two teeth
Show all characteristics

  • Flowers

    Bumps on fruit
    the perigynium surface has papillae on it
    Length of scale
    the scale is nearly as long as, or longer than, the perigynium
    Lowest spike length
    10–25 mm
    Lowest spike stalk length
    10–40 mm
    Lowest spike width
    5–8 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    0.4–0.5 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
    Perigynium beak teeth
    the perigynium beak is divided at the top into two teeth
    Perigynium beak teeth length
    Up to 0.5 mm
    Perigynium color
    brown
    Perigynium cross-section
    the perigynium is relatively round in cross-section
    Perigynium hairs
    the perigynium has no hairs
    Perigynium length
    2.5–3 mm
    Perigynium nerve number
    0
    Perigynium nerve texture
    NA
    Perigynium nerves lower side
    0
    Perigynium nerves upper side
    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
    1.5–1.75 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
    • brown
    • tan
    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
    Spikes per stem
    2-15
    Stigma branching
    the stigmas have three 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
    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
    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
    Lowest bract sheath
    the lowest bract has no sheath (or a very short sheath up to four millimeters in length)
    Lowest leaf blade width
    2.5–5 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    2.5–5 mm

  • Place

    Habitat
    • terrestrial
    • wetlands
    New England state
    • Maine
    • New Hampshire
    • Vermont
    Specific habitat
    • alpine or subalpine zones
    • cliffs, balds, or ledges
    • shores of rivers or lakes

  • Stem, shoot, branch

    Plant height
    20–70 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)

In New England

Distribution

Connecticut
absent
Maine
present
Massachusetts
absent
New Hampshire
present
Rhode Island
absent
Vermont
present

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Maine
rare to uncommon (S-rank: S2S3), special concern (code: SC)
New Hampshire
extremely rare (S-rank: S1), endangered (code: E)
Vermont
extremely rare (S-rank: S1), threatened (code: T)

From Flora Novae Angliae dichotomous key

162.  Carex atratiformis Britt. NC

scabrous black sedge. Carex atrata L. ssp. atratiformis (Britt.) Kükenth.; C. ovata Rudge 
• ME, NH, VT. Wet cliffs, river shores, and stream-side outcrops in high-pH bedrock areas, also 
of stream shores and wet rocks in subalpine communities.

Native to North America?

Yes

Sometimes confused with

Carex magellanica:
uppermost spike entirely staminate, perigynia beakless or with a beak to 0.2 mm, and carpellate scales usually awned (vs. C. atratiformis, with the uppermost spike gynecandrous, perigynia with beak 0.4-0.5 mm long, and carpellate scales pointed at the apex but usually unawned).

Synonyms

  • Carex atrata L. ssp. atratiformis (Britt.) Kükenth.
  • Carex ovata Rudge

Family

Cyperaceae

Genus

Carex