Carex atratiformis — scabrous black sedge
![Inflorescence: Carex atratiformis. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/carex-atratiformis-in-ahaines.jpg)
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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
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
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enlargeCharacteristics
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Maine
- New Hampshire
- Vermont
- 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
-
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 blade width
- 2.5–5 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 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)
-
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
Synonyms
- Carex atrata L. ssp. atratiformis (Britt.) Kükenth.
- Carex ovata Rudge