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- Carex michauxiana
Carex michauxiana — Michaux's sedge
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Facts
Michaux's sedge is a species of peat swamps and peaty shores. The yellowish green leaf blades have yellow-brown to brown sheaths, and the perigynia are long and lanceolate, 8.7 to 12.1 mm long by 1.3 to 2.1 mm wide. This species is endangered in Massachusetts.
Habitat
Bogs, fens, 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.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
- wetlands
- New England state
-
- Maine
- Massachusetts
- New Hampshire
- Vermont
- stem leaf blade width
- 1.6–4.2 mm
- Lowest bract sheath
- the lowest bract has a sheath longer than four millimeters
- Spike on stalk
- the lowest spike on the plant has a peduncle
- Top spike
- the uppermost spike contains only staminate flowers
- Perigynium hairs
- the perigynium has no hairs
- Perigynium length
- 8.7–12.1 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
- Anther length
- 1.1–2.7 mm
- Bumps on fruit
- there are no papillae on the perigynium surface
- Inflorescence length
- 18–180 mm
- Length of scale
- the scale is shorter than the perigynium
- Lowest spike length
- 15–25 mm
- Perigynium beak
- the perigynium has no beak, or an extremely short beak
- Perigynium beak length
- 0 mm
- Perigynium beak orientation
- NA
- Perigynium beak serrations
- NA
- Perigynium beak teeth
- the perigynium beak is divided at the top into two teeth
- Perigynium beak teeth length
- 1 mm
- Perigynium color
-
- green
- tan
- Perigynium cross-section
- the perigynium is relatively round in cross-section
- Perigynium hairs
- the perigynium has no hairs
- Perigynium length
- 8.7–12.1 mm
- Perigynium nerve number
- 20–26
- Perigynium nerve texture
- the nerves on the perigynium are raised, even after drying the perigynium
- Perigynium nerves lower side
- 10–13
- Perigynium nerves upper side
- 10–13
- Perigynium orientation
-
- the perigynia are angled outwards
- the perigynia are curved or bent downwards or backwards along the axis
- Perigynium puffy
- the achene is tightly enclosed by the perigynium
- Perigynium shape
- the perigynium body is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- Perigynium width
- 1.3–2.1 mm
- Perigynium winged
- the perigynium has no wings
- Pollen- and seed-producing spikes
- some of the spikes produce perigynia
- Pollen-producing spike length
- 6–15 mm
- Pollen-producing spike number
- 1
- Pollen-producing spike peduncle length
- At least 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
- green
- 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 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
- 2.2–3 mm
- Achene width
- 1.2–1.7 mm
- Style persistence
- the style stays on 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 flat or M-shaped, with two prominent side-veins
- Leaf blade texture
- the leaf blade is smooth and hairless, or rough and sandpapery
- Leaf bumps
- the upper surface of the leaf blade has papillae on it
- 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
- 1.2–3 mm
- Lowest bract sheath
- the lowest bract has a sheath longer than four millimeters
- Lowest leaf blade width
- 1.6–4.2 mm
- Lowest leaf sheath texture
- the leaf sheath feels smooth (it may have soft hairs)
- stem leaf blade width
- 1.6–4.2 mm
-
Place
- Habitat
- wetlands
- New England state
-
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Specific habitat
-
- bogs
- fens
- shores of rivers or lakes
-
Stem, shoot, branch
- Plant height
- 15–70 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
Occurs only in wetlands. (Wetland indicator code: OBL)
In New England
Distribution
- Connecticut
- absent
- Maine
- present
- Massachusetts
- present
- 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.
- Massachusetts
- extremely rare (S-rank: S1), endangered (code: E)
- New Hampshire
- uncommon (S-rank: S3), W (code: W)
- Vermont
- rare (S-rank: S2)
From Flora Novae Angliae dichotomous key
166. Carex michauxiana Boeckl. N
Michaux’s sedge. Carex abacta Bailey • MA, ME, NH, VT. Peatlands, lakeside fens, peaty shores.
Native to North America?
Yes
Sometimes confused with
- Carex folliculata:
- widest leaf blades mostly 6-18 mm wide and upper leaf sheaths convex at the summit (vs. C. michauxiana, with widest leaf blades mostly 1.6-3.5 mm wide and upper leaf sheaths concave at the summit).
Synonyms
- Carex abacta Bailey