Schoenoplectus etuberculatus — Canby's club-bulrush
![Flowers and fruits: Schoenoplectus etuberculatus. ~ By Julian A. Steyermark. ~ Copyright © 2024. ~ Allison Brock, Allison.Brock[at]mobot.org ~ Steyermark, Julian A. 1963. The Flora of Missouri. The Iowa State U. Press, Ames, IA. 1725pp.](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/schoenoplectus-etuberculatus-ff-jsteyermark1.jpg)
![Inflorescences: Schoenoplectus etuberculatus. ~ By Julian A. Steyermark. ~ Copyright © 2024. ~ Allison Brock, Allison.Brock[at]mobot.org ~ Steyermark, Julian A. 1963. The Flora of Missouri. The Iowa State U. Press, Ames, IA. 1725pp.](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Cyperaceae/schoenoplectus-etuberculatus-in-jsteyermark1.jpg)
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Facts
Canby's bulrush, a wetland plant of the coastal plain, enters New England only via a single population, located in southern Rhode Island. This is unusual because it is more than two hundred and fifty miles from the next population in Delaware. It occurs on pond shores and marshes along the coastal plain.
Habitat
Brackish or salt marshes and flats, fresh tidal marshes or flats, marshes, 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.
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enlargeCharacteristics
- Habitat
-
- aquatic
- wetlands
- New England state
- Rhode Island
- Stem shape in cross-section
- the stem is roughly triangular in cross-section
- Leaf blade width
- 2–10 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 appears to come from the side of the plant because the involucral bract at its base looks like an extension of the main stem
- Inflorescence branching
- the inflorescence is branched
- Fruit type (general)
- the fruit is like a seed, and surrounded by scales
- Fruit length
- 3–4.5 mm
- Leaf position on plant
- the attachment points of all the leaves are at or near the base of the plant
- Perianth composition
- there are bristles attached at the base of the achene
- Fruit cross-section
- the fruit is triangular to terete (circular) in cross-section
-
Flowers
- Anther length
- 3–3.5 mm
- Floral bristle color
- the bristles are slightly or strongly colored with reddish brown
- Floral bristle number
- 5-7
- Floral bristle relative length
- the bristles are between one tenth as long as the achene, and equal in length to the achene
- Floral bristles
- the bristles are straight or slightly curved
- Floral scale hairs
- the floral scales have hairs on them
- Floral scale length
- 5–7 mm
- Floral scale nerves
-
- 2-5
- 7 or more
- Floral scale shape
-
- the floral scales are lanceolate (widest below the middle, and tapering at both ends)
- the floral scales are ovate (roughly egg-shaped)
- Floral scale translucent
- the floral scales are opaque
- 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 is only one bract, and it looks like a continuation of the stem
- 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 appears to come from the side of the plant because the involucral bract at its base looks like an extension of the main stem
- 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 are bristles attached at the base of the achene
- Stamen number
- 3
- Stigma number
- 3
- Style division
- the top two thirds of the style is divided
- floral bristle barbs
- the bristles have tiny barbs on them
- plantlets budding at flower bases
- no
-
Fruits or seeds
- Achene beak length
- 0.7–2 mm
- Achene surface texture
- the achene is smooth (it has no detectable texture)
- Achene tubercle relative width
- NA
- Achene tubercle width
- 0 mm
- Capsule relative length
- NA
- Fruit cross-section
- the fruit is triangular to terete (circular) in cross-section
- Fruit length
- 3–4.5 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) without a tubercle (a swelling or projection, usually of a different color or texture)
- Locules in capsule
- NA
- Seed length
- 0 mm
- Seed tail relative length
- 0 mm
- Seed tails
- NA
- Tubercle height
- 0 mm
-
Growth form
- Lifespan
- the plant lives more than two years
- Rhizome thickness
- 1–3 mm
- Underground organs
- the plant has a rhizome (a horizontal underground stem with roots growing from it)
-
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 length
- Up to 80 mm
- Leaf blade width
- 2–10 mm
- Leaf form
- all the leaves hold their form out of water
- Leaf position on plant
- the attachment points of all the leaves are at or near the base of the plant
- 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 blade ligules
- the plant has ligules at the leaf blade bases
- Stem leaf blades
-
- there are fully-developed leaves with leaf blades on the main stem
- there are no leaves on the main stem, or there is a small tooth or tiny blade, or a leaf sheath with no blade
-
Place
- Habitat
-
- aquatic
- wetlands
- New England state
- Rhode Island
- Specific habitat
-
- brackish or salt marshes and flats
- fresh tidal marshes or flats
- marshes
- shores of rivers or lakes
-
Stem, shoot, branch
- Plant height
- 60–200 cm
- Stem shape in cross-section
- the stem is roughly triangular in cross-section
- Stem texture near tip
- the stem feels smooth near the tip
- Stem thickness at midpoint
- 1–10 mm
Wetland status
Occurs only in wetlands. (Wetland indicator code: OBL)
In New England
Distribution
- Connecticut
- absent
- Maine
- absent
- Massachusetts
- absent
- New Hampshire
- absent
- Rhode Island
- present
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Rhode Island
- extremely rare (S-rank: S1), state endangered (code: SE)
From Flora Novae Angliae dichotomous key
3. Schoenoplectus etuberculatus (Steud.) Soják NC
Canby’s club-bulrush. Scirpus etuberculatus (Steud.) Kuntze • RI. Pond shores and fresh to brackish marshes along the coastal plain.
Native to North America?
Yes
Sometimes confused with
- Schoenoplectus torreyi:
- inflorescence congested, lacking elongate branches, usually with 1–4 spikelets, floral scales 4–5 mm long, and style beak 0.5–1 mm long (vs. S. etuberculatus, with the inflorescence open, with elongate branches, with 3–20 pedicellate spikelets, floral scales 5–7 mm long, and style beak 0.7–2 mm long).
Synonyms
- Scirpus etuberculatus (Steud.) Kuntze