Carex adusta — swarthy sedge
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Facts
Swarthy sedge is distributed across Canada and some northern states of the United States. It grows in dry, sandy soils of woodlands, road shoulders and old road beds in Maine and New Hampshire.
Habitat
Anthropogenic (man-made or disturbed habitats), woodlands
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
- New England state
-
- Maine
- New Hampshire
- stem leaf blade width
- 2–3.5 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 is not borne on 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
- 4–5 mm
- Leaf sheath color
- the leaf sheath has no pink, red or purple tinting
- 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
- there are no papillae on the perigynium surface
- Inflorescence length
- 20–45 mm
- Length of scale
- the scale is nearly as long as, or longer than, the perigynium
- Lowest spike length
- 8–11 mm
- Lowest spike stalk length
- 0 mm
- Lowest spike width
- 5–8 mm
- Perigynium beak
- the perigynium has a beak
- 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 divided at the top into two teeth
- Perigynium color
-
- green
- tan
- yellow
- Perigynium cross-section
-
- the perigynium is biconvex (convexly rounded on both sides, like a lens) in cross-section
- the perigynium is planoconvex (flat on one surface and rounded on the other) in cross-section
- Perigynium hairs
- the perigynium has no hairs
- Perigynium length
- 4–5 mm
- Perigynium nerve number
- 7–13
- Perigynium nerve texture
- the nerves on the perigynium are raised, even after drying the perigynium
- Perigynium nerves lower side
- 7–11
- Perigynium nerves upper side
- 0–2
- Perigynium orientation
-
- the perigynia are angled outwards
- the perigynia are oriented vertically or pressed against the axis or adjacent perigynia
- Perigynium puffy
- the achene is tightly enclosed by the perigynium
- Perigynium shape
- the perigynium body is ovate (egg-shaped)
- Perigynium width
- 1.9–2.5 mm
- Perigynium winged
- the perigynium has wings on it
- 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
- red-brown
- Scale length
- 4–5.5 mm
- Scale tip
- the carpellate scale tip is acute (has a sharp point)
- Spike on stalk
- the lowest spike on the plant is not borne on a peduncle
- Spike orientation
- the spikes are oriented vertically or pressed against the axis
- Spikes per stem
- 2-15
- Stigma branching
- the stigmas have two 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
- Achene length
- 2.1–2.5 mm
- Achene width
- 1.6–2 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 folded lengthwise, with one prominent midvien
- Leaf blade length to width ratio
- 35–71
- 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 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
- Ligule length
- 1–4 mm
- Lowest bract sheath
- the lowest bract has no sheath (or a very short sheath up to four millimeters in length)
- Lowest leaf blade width
- 2–3.5 mm
- Lowest leaf sheath texture
- the leaf sheath feels smooth (it may have soft hairs)
- stem leaf blade width
- 2–3.5 mm
-
Place
- Habitat
- terrestrial
- New England state
-
- Maine
- New Hampshire
- Specific habitat
-
- man-made or disturbed habitats
- woodlands
-
Stem, shoot, branch
- Plant height
- 25–80 cm
- Relative stem height
- the main stem is taller than the leaves
- Spike internode length
- 2–15 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
In New England
Distribution
- Connecticut
- absent
- Maine
- present
- Massachusetts
- absent
- New Hampshire
- present
- Rhode Island
- absent
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Maine
- rare (S-rank: S2), endangered (code: E)
- New Hampshire
- historical (S-rank: SH), endangered (code: E)
From Flora Novae Angliae dichotomous key
34. Carex adusta Boott NC
swarthy sedge. ME, NH. Sandy, often well-drained, soils of woodlands, road shoulders, old road beds, and borrow pits.
Native to North America?
Yes
Sometimes confused with
- Carex foenea:
- carpellate scales narrower than the perigynia they subtend and achenes 1.2-1.6 mm wide (vs. C. adusta, with carpellate scales as wide as the perigynia they subtend and achenes 1.6-2 mm wide).