Rhynchospora nitens (Vahl) Gray

short-beaked beaksedge

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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

Short-beaked beaksedge is an annual sedge that is rare in New England, being known only from a few populations on coastal plain pond shores in eastern Massachusetts. It appears only in years of unusually low water levels, germinating in sandy or muddy shorelines, and remaining only as a dormant seed bank until the next instance of low water levels. For a rare plant, this species is unusual in that there have been recent discoveries of new and larger populations than previously known. Threats include development, recreation, and changes in pond hydrology, as well as nutrient runoff.

Habitat

Shores of rivers or lakes

Characteristics

Habitat
  • aquatic
  • wetlands
New England state
Massachusetts
Stem shape in cross-section
the stem is round or oval in cross-section
Leaf blade width
1–5 mm
Leaf blade cross-section
  • the leaf blade is flat or rolled in at the edges
  • the leaf blade is triangular in cross-section
Inflorescence position
  • the inflorescence emerges from an axil, or most of its parts do so
  • the inflorescence is at the tip of the plant
Inflorescence branching
the inflorescence is branched
Fruit type (general)
the fruit is like a seed, and surrounded by scales
Fruit length
1–1.5 mm
Leaf position on plant
some leaf attachment points are above the midpoint of the stem
Perianth composition
there is no perianth on the plant
Fruit cross-section
the fruit is biconvex or elliptic (widest in the middle and tapering to both ends) in cross-section
Show All Characteristics
  • Flowers
    Floral bristle color
    NA
    Floral bristle number
    0
    Floral bristle relative length
    NA
    Floral bristles
    NA
    Floral scale hairs
    there are no hairs on the floral scales
    Floral scale length
    2–3.5 mm
    Floral scale nerves
    1
    Floral scale shape
    the floral scales are ovate (roughly egg-shaped)
    Inflorescence bract angle
    the bracts are vertical or angled only slightly outwards
    Inflorescence bract number
    there are two to five bracts per inflorescence
    Inflorescence bract position (Sparganium)
    NA
    Inflorescence bracts
    there are at least two bracts, and they are either flat or folded or rolled in at the edges
    Inflorescence branching
    the inflorescence is branched
    Inflorescence crowding
    the inflorescence is at least somewhat spread out, with at least one branch coming from the main stem
    Inflorescence position
    • the inflorescence emerges from an axil, or most of its parts do so
    • the inflorescence is at the tip of the plant
    Inflorescence shape
    the aggregations within the inflorescence are roughly circular (not flattened) in cross-section
    Inflorescence type
    there are two or more flowers, spikes or flower clusters on a branched inflorescence
    Perianth composition
    there is no perianth on the plant
    Stamen number
    • 2
    • 3
    Stigma number
    2
    Style division
    the top two thirds of the style is divided
    floral bristle barbs
    NA
    plantlets budding at flower bases
    no
  • Fruits or seeds
    Achene beak length
    0 mm
    Achene surface texture
    the achene has tiny wrinkles that run cross-wise across the achene
    Achene tubercle relative width
    the tubercle is two thirds to about as wide as the achene
    Capsule relative length
    NA
    Fruit cross-section
    the fruit is biconvex or elliptic (widest in the middle and tapering to both ends) in cross-section
    Fruit length
    1–1.5 mm
    Fruit type (general)
    the fruit is like a seed, and surrounded by scales
    Fruit type (specific)
    the fruit is an achene (dry, seed-like fruit) with a tubercle (a swelling or projection, usually of a different color or texture) on it
    Locules in capsule
    NA
    Seed length
    0 mm
    Seed tail relative length
    0 mm
    Seed tails
    NA
    Tubercle height
    0.1–0.3 mm
  • Growth form
    Lifespan
    the plant lives only a single year or less
    Rhizome thickness
    0 mm
    Underground organs
    there are only slender roots on the plant
  • Leaves
    Auricle length
    0 mm
    Auricle texture
    NA
    Auricles
    there are no auricles on the leaf sheath
    Leaf blade cross-section
    • the leaf blade is flat or rolled in at the edges
    • the leaf blade is triangular in cross-section
    Leaf blade width
    1–5 mm
    Leaf form
    all the leaves hold their form out of water
    Leaf position on plant
    some leaf attachment points are above the midpoint of the stem
    Leaf septa
    the leaf blades do not have transverse septa
    Leaf sheath hairs
    the leaf sheathes are without hairs
    Pedicel length (Typha)
    0 mm
    Stem leaf blades
    there are fully-developed leaves with leaf blades on the main stem
  • Place
    Habitat
    • aquatic
    • wetlands
    New England state
    Massachusetts
    Specific habitat
    shores of rivers or lakes
  • Stem, shoot, branch
    Plant height
    10–100 cm
    Stem shape in cross-section
    the stem is round or oval in cross-section
    Stem texture near tip
    the stem feels smooth near the tip

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
absent
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)

Native to North America?

Yes

Synonyms

  • Psilocarya nitens (Vahl) Wood

Family

Cyperaceae

Genus

Rhynchospora

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Information from Dichotomous Key of Flora Novae Angliae

7.  Rhynchospora nitens (Vahl) Gray NC

short-beaked beaksedge. Psilocarya nitens (Vahl) Wood • MA. Coastal plain pond shores.