Carex mitchelliana — Mitchell's sedge
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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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enlargeFacts
Mitchell's sedge is found in deciduous and evergreen swamps, marshes, stream banks and shores in Massachusetts and Rhode Island. New England is the northern limit of its range, but it is uncommon throughout its range, being known from less than 100 extinct and extant populations.
Habitat
Marshes, shores of rivers or lakes, swamps
Characteristics
- Habitat
- wetlands
- New England state
-
- Massachusetts
- Rhode Island
- stem leaf blade width
- 3–8 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 only staminate flowers
- Perigynium hairs
- the perigynium has no hairs
- Perigynium length
- 2.5–3.9 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 not divided at the tip into two teeth, or the teeth are very tiny
-
Flowers
- Bumps on fruit
- the perigynium surface has papillae on it
- Lowest spike length
- 31–79 mm
- Lowest spike stalk length
- 6–30 mm
- Lowest spike width
- 3.6–7.4 mm
- Perigynium beak
- the perigynium has a beak
- Perigynium beak length
- 0.1–0.3 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 not divided at the tip into two teeth, or the teeth are very tiny
- Perigynium beak teeth length
- 0 mm
- Perigynium color
- tan
- 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
- 2.5–3.9 mm
- Perigynium nerve number
- 0–5
- Perigynium nerve texture
-
- NA
- the nerves on the perigynium are raised, even after drying the perigynium
- Perigynium nerves lower side
- 0–5
- 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 ovate (egg-shaped)
- 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
- Up to 50 mm
- Pollen-producing spike number
- 1–2
- Scale awn
- the carpellate scale has an awn on it
- Scale awn texture
- the carpellate scale awn has tiny teeth
- Scale color
-
- brown
- red-brown
- tan
- Scale length
- 2.9–6.3 mm
- Scale tip
- the carpellate scale tip is rounded to retuse (blunt or rounded, with a notch at the tip)
- Spike on stalk
- the lowest spike on the plant has a peduncle
- Spike orientation
- the spikes are bent downwards or droop downwards
- Spikes per stem
- 2-15
- Stigma branching
- the stigmas have two branches
- Top spike
- the uppermost spike contains only staminate 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 no rhizomes, or the rhizomes are very short
-
Leaves
- Leaf arrangement
- the leaves are mostly produced higher up on the plant
- Leaf blade length to width ratio
- 43–44
- 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 rough, or has 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
- 3–8 mm
- Lowest leaf sheath texture
- the leaf sheath feels rough
- stem leaf blade width
- 3–8 mm
-
Place
- Habitat
- wetlands
- New England state
-
- Massachusetts
- Rhode Island
- Specific habitat
-
- marshes
- shores of rivers or lakes
- swamps
-
Stem, shoot, branch
- Plant height
- 40–140 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)
New England distribution and conservation status
Distribution
- Connecticut
- absent
- Maine
- absent
- Massachusetts
- present
- New Hampshire
- absent
- Rhode Island
- present
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- rare (S-rank: S2), threatened (code: T)
- Rhode Island
- extremely rare (S-rank: S1), concern (uncertain) (code: C*)
Native to North America?
Yes
Sometimes confused with
- Carex gynandra:
- perigynia smooth to weakly papillose and achenes with a constriction (vs. C. mitchelliana, with perigynia densely papillose and achenes without a constriction).
- Carex crinita:
- lower leaf sheaths smooth and perigynia smooth to weakly papillose (vs. C. mitchelliana, with the lower leaf sheaths scabrous due to minute, stiff hairs and perigynia densely papillose).
Synonyms
- Carex crinita Lam. var. mitchelliana (M.A. Curtis) Gleason
Family
Genus
From the dichotomous key of Flora Novae Angliae
137. Carex mitchelliana M.A. Curtis NC
Mitchell’s sedge. Carex crinita Lam. var. mitchelliana (M.A. Curtis) Gleason • MA, RI. Swamps, both deciduous and evergreen types, stream banks, shorelines, and graminoid marshes.