Rhynchospora nitens — short-beaked beaksedge
![Inflorescences: Rhynchospora nitens. ~ By Bruce Sorrie. ~ Copyright © 2024 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/rhynchospora-nitens-in-bsorrie.jpg)
![Flowers and fruits: Rhynchospora nitens. ~ By Elizabeth Farnsworth. ~ Copyright © 2024 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/rhynchospora-nitens-ff-efarnsworth.jpg)
![Leaves and auricles: Rhynchospora nitens. ~ By John Bradford and George Rogers. ~ Copyright © 2024 John Bradford and George Rogers. ~ George Rogers: rogersg[at]palmbeachstate.edu, 561-207-5052 ~ floridagrasses.org/index.htm](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/rhynchospora-nitens-la-flgrasses1.jpg)
![Plant form: Rhynchospora nitens. ~ By Bruce Sorrie. ~ Copyright © 2024 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/rhynchospora-nitens-ha-bsorrie.jpg)
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Facts
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
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.
Found this plant? Take a photo and post a sighting.
enlargeCharacteristics
- 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
-
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)
In New England
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)
From Flora Novae Angliae dichotomous key
7. Rhynchospora nitens (Vahl) Gray NC
short-beaked beaksedge. Psilocarya nitens (Vahl) Wood • MA. Coastal plain pond shores.
Native to North America?
Yes
Sometimes confused with
- Rhynchospora scirpoides:
- tubercle narrow-triangular, 0.5–0.9 mm tall, achene body obscurely transverse-rugose, with the marginal edges flowing into the tubercle base (vs. R. nitens, with tubercle depressed-triangular, 0.1–0.3 mm tall, achene body distinctly but irregularly transverse-rugose, with the marginal edges interrupted at the tubercle base).
- Rhynchospora torreyana:
- plants perennial, perianth bristles present but sometimes caducous, inflorescences of remote to congested clusters of spikes, and spikes usually clustered (vs. R. nitens, the plants annual, perianth bristles absent, inflorescences open, diffuse, cyme-like or panicle-like, and spikes stalked).
Synonyms
- Psilocarya nitens (Vahl) Wood