Carex tonsa (Fern.) Bickn.

shaved 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

There are two varieties of shaved sedge in New England, (Carex tonsa var. tonsa and C. tonsa var. rugosperma), with overlapping ranges in New England. They may be found growing together.

Habitat

Cliffs, balds, or ledges, forests, grassland, woodlands

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Vermont
stem leaf blade width
0.5–4.3 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 has a peduncle
  • the lowest spike on the plant is not borne on a peduncle
Top spike
the uppermost spike contains only staminate flowers
Perigynium hairs
the perigynium is hairy
Perigynium length
3.1–4.7 mm
Leaf sheath color
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
    1.6–2.9 mm
    Bumps on fruit
    there are no papillae on the perigynium surface
    Length of scale
    the scale is nearly as long as, or longer than, the perigynium
    Lowest spike length
    4–10 mm
    Perigynium beak
    the perigynium has a beak
    Perigynium beak length
    0.9–2 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
    0.2–0.5 mm
    Perigynium color
    • brown
    • green
    Perigynium cross-section
    the perigynium is trigonous (triangular) in cross-section
    Perigynium hairs
    the perigynium is hairy
    Perigynium length
    3.1–4.7 mm
    Perigynium nerve number
    0–2
    Perigynium nerve texture
    NA
    Perigynium nerves lower side
    0
    Perigynium nerves upper side
    0
    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 elliptic (widest near the middle and tapering at both ends)
    Perigynium width
    1.1–1.6 mm
    Perigynium winged
    the perigynium has no wings
    Pollen- and seed-producing spikes
    some of the spikes produce perigynia
    Pollen-producing spike length
    4.5–11.3 mm
    Pollen-producing spike number
    1
    Pollen-producing spike peduncle length
    0.8–15 mm
    Pollen-producing spike width
    1.1–3 mm
    Scale awn
    The carpellate scale does not have an awn (it may have a short point)
    Scale awn texture
    NA
    Scale color
    • brown
    • red-brown
    Scale length
    2.9–4.1 mm
    Scale tip
    • the carpellate scale tip is acuminate (tapered to a narrow point)
    • the carpellate scale tip is acute (has a sharp point)
    Spike on stalk
    • the lowest spike on the plant has a peduncle
    • 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
    Staminate scale tip
    • the staminate scale tip is acuminate (tapered to a narrow point)
    • the staminate scale tip is acute (has a sharp point)
    • the staminate scale tip is obtuse (has a blunt point)
    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
    1.6–2 mm
    Achene width
    1.2–1.6 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 folded lengthwise, with one prominent midvien
    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
    • the upper surface of the leaf blade has papillae on it
    Leaf sheath bumps
    • the top edge of the leaf sheath has papillae on it
    • there are no papillae at the top edge of the leaf sheath
    Leaf sheath color
    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
    0.5–4.3 mm
    Lowest leaf sheath texture
    the leaf sheath feels smooth (it may have soft hairs)
    stem leaf blade width
    0.5–4.3 mm
  • Place
    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Vermont
    Specific habitat
    • cliffs, balds, or ledges
    • forests
    • grasslands
    • woodlands
  • Stem, shoot, branch
    Plant height
    4–16 cm
    Relative stem height
    the main stem is equal to or shorter 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

Not classified

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.

var. tonsa

Massachusetts
unranked (S-rank: SNR)
Vermont
extremely rare (S-rank: S1)

Native to North America?

Yes

Sometimes Confused With

Carex umbellata:
perigynium 2.2-3.2 mm long with a beak 0.4-1 mm long (vs. C. tonsa, with a perigynium 3.1-4.7 mm long with a beak 0.9-2 mm long).

Synonyms

  • Carex rugosperma Mackenzie var. tonsa (Fern.) E.G. Voss
  • Carex umbellata var. tonsa Fern.

Family

Cyperaceae

Genus

Carex

Notes on Subspecies and Varieties in New England

Carex tonsa var. rugosperma (Mackenzie) W.J. Crins Carex tonsa var. tonsa (Fern.) Bickn.

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Information from Dichotomous Key of Flora Novae Angliae

10.  Carex tonsa (Fern.) Bickn. N

shaved sedge.  10a. Carex rugosperma Mackenzie;  10b. Carex rugosperma Mackenzie var. tonsa (Fern.) E.G. Voss; Carex umbellata Schkuhr ex Willd. var. tonsa Fern. • CT, MA, ME, NH, VT. Sandy grasslands and heathlands, xeric to mesic forests and woodlands, rocky balds.

1a.  Leaf blades stiff, coriaceous, smooth or slightly scabrous adaxially, pale green; perigynia nearly glabrous, usually with a few hairs near the base of the beak 
 … 10a. C. tonsa var. tonsa

1b.  Leaf blades soft, herbaceous, scabrous or papillose adaxially, bright green; perigynia pubescent on the body as well as the beak 
 … 10b. C. tonsa var. rugosperma (Mackenzie) W.J. Crins