Carex mackenziei Krecz.

Mackenzie's sedge

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New England Distribution

Adapted from BONAP data

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North America Distribution

Adapted from BONAP data

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Facts About

Within New England, Mackenzie' s sedge is found only in brackish and salt marshes of Maine. It is loosely clumping and often has long stolons.

Habitat

Brackish or salt marshes and flats, marshes

Characteristics

Habitat
wetlands
New England state
Maine
stem leaf blade width
1–3 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
2.5–3.3 mm
Leaf sheath color
  • the leaf sheath has no pink, red or purple tinting
  • 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
  • the perigynium beak is not divided at the tip into two teeth, or the teeth are very tiny
Show All Characteristics
  • Flowers
    Bumps on fruit
    there are no papillae on the perigynium surface
    Distance between perigynia
    10–15 mm
    Inflorescence length
    15–50 mm
    Length of scale
    the scale is nearly as long as, or longer than, the perigynium
    Lowest spike length
    5–15 mm
    Lowest spike stalk length
    0 mm
    Lowest spike width
    4–6 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 divided at the top into two teeth
    • the perigynium beak is not divided at the tip into two teeth, or the teeth are very tiny
    Perigynium beak teeth length
    At least 0 mm
    Perigynium color
    tan
    Perigynium 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
    2.5–3.3 mm
    Perigynium nerve texture
    the nerves on the perigynium are raised, even after drying the perigynium
    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 oblong (rectangular but with rounded ends)
    Perigynium width
    1.5–2 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
    red-brown
    Scale tip
    the carpellate scale tip is obtuse (has a blunt 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
    1.75–2 mm
    Achene width
    1.25–1.5 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 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 length to width ratio
    50–66
    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
    • 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
    1–3 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    1–3 mm
  • Place
    Habitat
    wetlands
    New England state
    Maine
    Specific habitat
    • brackish or salt marshes and flats
    • marshes
  • Stem, shoot, branch
    Plant height
    10–40 cm
    Relative stem height
    • the main stem is equal to or shorter than the leaves
    • 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)

New England Distribution and Conservation Status

Distribution

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

Conservation Status

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

Maine
extremely rare (S-rank: S1), endangered (code: E)

Native to North America?

Yes

Sometimes Confused With

Carex brunnescens

Synonyms

  • Carex norvegica Willd. ex Schkuhr

Family

Cyperaceae

Genus

Carex

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Information from Dichotomous Key of Flora Novae Angliae

71.  Carex mackenziei Krecz. N

Mackenzie’s sedge. Carex norvegica Willd. ex Schkuhr • ME. Brackish and saline marshes.

70×71. Carex canescens × Carex mackenziei Carex ×‌pseudohelvola Kihlm. is a rare sedge hybrid that is known from ME. 
It is similar to C. mackenziei in that the carpellate scales ± equal the perigynia and cover them. However, the hybrid differs from that species in its scabrous upper angles 
of the stem and the carpellate scales that are weakly tinged with red-brown.