Carex lupulina Muhl. ex Willd.

hop 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

Hop sedge inhabits the eastern half of North America, where it is found in marshy lakeshores, swamp openings and grassy marshes. Its achenes provide food for waterfowl.

Habitat

Marshes, shores of rivers or lakes, swamps

Characteristics

Habitat
wetlands
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
stem leaf blade width
4–15 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
11–19 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
Show All Characteristics
  • Flowers
    Anther length
    3–5.5 mm
    Bumps on fruit
    there are no papillae on the perigynium surface
    Inflorescence length
    40–400 mm
    Length of scale
    • the scale is nearly as long as, or longer than, the perigynium
    • the scale is shorter than the perigynium
    Lowest spike length
    15–65 mm
    Lowest spike stalk length
    5–200 mm
    Lowest spike width
    13–30 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    6–10 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
    • the perigynium beak has tiny serrations along the edges
    Perigynium beak teeth
    the perigynium beak is divided at the top into two teeth
    Perigynium beak teeth length
    Up to 1 mm
    Perigynium color
    green
    Perigynium cross-section
    the perigynium is relatively round in cross-section
    Perigynium hairs
    the perigynium has no hairs
    Perigynium length
    11–19 mm
    Perigynium nerve number
    13–22
    Perigynium nerve texture
    the nerves on the perigynium are raised, even after drying the perigynium
    Perigynium nerves lower side
    6–11
    Perigynium nerves upper side
    6–11
    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 lanceolate (lance-shaped; widest below the middle and tapering at both ends)
    • the perigynium body is ovate (egg-shaped)
    Perigynium width
    3–6 mm
    Perigynium winged
    the perigynium has no wings
    Pollen- and seed-producing spikes
    some of the spikes produce perigynia
    Pollen-producing spike length
    15–85 mm
    Pollen-producing spike number
    1–2
    Pollen-producing spike peduncle length
    5–70 mm
    Pollen-producing spike width
    1–5 mm
    Scale awn
    the carpellate scale has an awn on it
    Scale awn texture
    the carpellate scale awn has tiny teeth
    Scale color
    • green
    • white or translucent
    Scale length
    6–15 mm
    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
    3–4.5 mm
    Achene width
    1.7–2.8 mm
    Style persistence
    the style stays on 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 folded lengthwise, with one prominent midvien
    Leaf blade length to width ratio
    38–42
    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
    Ligule length
    3.5–18 mm
    Lowest bract sheath
    the lowest bract has a sheath longer than four millimeters
    Lowest leaf blade width
    4–15 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    4–15 mm
  • Place
    Habitat
    wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • marshes
    • shores of rivers or lakes
    • swamps
  • Stem, shoot, branch
    Plant height
    20–130 cm
    Relative stem height
    • the main stem is equal to or shorter than the leaves
    • the main stem is taller than the leaves
    Spike internode length
    10–200 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
    • the stems grow singly or a few together (they may form diffuse colonies)

Wetland Status

Occurs only in wetlands. (Wetland indicator code: OBL)

New England Distribution and Conservation Status

Distribution

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

Conservation Status

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

Maine
unranked (S-rank: SNR)
Massachusetts
unranked (S-rank: SNR)

Native to North America?

Yes

Sometimes Confused With

Carex lupuliformis:
achenes nearly as wide as long, each angle with a prominent, knob-like point (vs. C. lupulina, with achenes longer than wide, the angles without knob-like points).

Synonyms

  • Carex lupulina var. pedunculata Gray

Family

Cyperaceae

Genus

Carex

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Information from Dichotomous Key of Flora Novae Angliae

112.  Carex lupulina Muhl. ex Willd. N

hop sedge. Carex lupulina Muhl. ex Willd. var. pedunculata Gray • CT, MA, ME, NH, RI, VT. 
Marshy lake shores, openings in swamps, graminoid marshes.

112×182. Carex lupulina × Carex lurida This rare sedge hybrid is known from CT, MA, ME, VT. It appears similar to 
 Carex lupulina but with smaller spikes, shorter than average perigynia (9.5–13 mm long vs. 11–19 mm long), and carpellate scales always with a prominent, scabrous awn.