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- Cyperus
- Cyperus retrorsus
Cyperus retrorsus — pine barren flatsedge
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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.
Facts
Pine barren flatsedge is very rare in New England, which represents the northern limit of its mainly southeastern range. There are a few populations in Martha's Vineyard on sandy soils and trail edges. It loosely resembles Cyperus echinatus because of its rounded inflorescences, but it is a small plant with more cylindrical inflorescences. Look for its fruits between June and August.
Habitat
Anthropogenic (man-made or disturbed habitats), woodlands
Characteristics
- Habitat
- terrestrial
- New England state
- Massachusetts
- Stem shape in cross-section
- the stem is roughly triangular in cross-section
- Leaf blade width
- 1.5–5 mm
- Leaf blade cross-section
- the leaf blade is flat or rolled in at the edges
- Inflorescence position
- the inflorescence is at the tip of the plant
- Inflorescence branching
-
- the inflorescence is branched
- the inflorescence is on one or more stems with no branches
- Fruit type (general)
- the fruit is like a seed, and surrounded by scales
- Fruit length
- 1.2–1.7 mm
- Leaf position on plant
- the attachment points of all the leaves are at or near the base of the plant
- Perianth composition
- there is no perianth on the plant
- Fruit cross-section
- the fruit is triangular to terete (circular) in cross-section
-
Flowers
- Anther length
- 0.3–0.5 mm
- 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
- 1.8–2.5 mm
- Floral scale nerves
-
- 1
- 2-5
- Floral scale shape
-
- the floral scales are oblong (rectangular but with rounded ends)
- the floral scales are ovate (roughly egg-shaped)
- Floral scale translucent
- the floral scales are opaque
- Flower number per cluster
- more than 20
- 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
- the inflorescence is on one or more stems with no branches
- Inflorescence crowding
- the inflorescence is crowded together in one tight cluster
- Inflorescence position
- the inflorescence is at the tip of the plant
- Inflorescence shape
- the aggregations within the inflorescence are at least somewhat flattened in cross-section
- Inflorescence type
-
- there are two or more flowers, spikes or flower clusters on a branched inflorescence
- there is one spike or raceme at the tip of the stem
- Perianth composition
- there is no perianth on the plant
- Stamen number
-
- 1
- 2
- 3
- Stigma number
- 3
- 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 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
- 1.2–1.7 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
- 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
- Leaf blade length
- 100–550 mm
- Leaf blade width
- 1.5–5 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
- there are no ligules at the leaf blade bases
- Stem leaf blades
- there are fully-developed leaves with leaf blades on the main stem
- Width of seed-producing inflorescence
- 4–16 mm
-
Place
- Habitat
- terrestrial
- New England state
- Massachusetts
- Specific habitat
-
- man-made or disturbed habitats
- woodlands
-
Stem, shoot, branch
- Plant height
- 20–85 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
Wetland status
Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)
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
- extremely rare (uncertain) (S-rank: S1?), #NAME? (code: #NAME?)
Native to North America?
Yes
Sometimes confused with
Synonyms
- Cyperus cylindricus (Ell.) Britt.
- Mariscus cylindricus Ell.
- Mariscus retrorsus (Chapman) C.B. Clarke
Family
Genus
From the dichotomous key of Flora Novae Angliae
19. Cyperus retrorsus Chapman NC
pine barren flatsedge. Cyperus cylindricus (Ell.) Britt.; Mariscus cylindricus Ell.; M. retrorsus (Chapman) C.B. Clarke • MA; Marthas Vineyard. Sandy soil of woodlands, clearings, and trail edges.