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- Carex
- Carex Group 6
- Section Ceratocystis
- Carex flava
Carex flava — yellow-green sedge
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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.
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Facts
Yellow-green sedge may get its name from the perigynia (coverings of the seeds), which have a yellow body and a green or yellow beak. It is an obligate wetland species that prefers high-pH sites.
Habitat
Meadows and fields, ridges or ledges, shores of rivers or lakes
Characteristics
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- stem leaf blade width
- 1.6–5.8 mm
- Lowest bract sheath
-
- the lowest bract has a sheath longer than four millimeters
- 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 both staminate and carpellate flowers, with the carpellate flowers located below, or intermixed with, the staminate flowers
- the uppermost spike contains only staminate flowers
- Perigynium hairs
-
- the perigynium has no hairs
- the perigynium is hairy
- Perigynium length
- 4–6.3 mm
- Leaf sheath color
- the leaf sheath has no pink, red or purple tinting
- 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
-
Flowers
- Anther length
- 1–2.1 mm
- Bumps on fruit
- there are no papillae on the perigynium surface
- Length of scale
- the scale is shorter than the perigynium
- Lowest spike length
- 8–22 mm
- Lowest spike stalk length
- At least 0 mm
- Lowest spike width
- 7.5–12.7 mm
- Perigynium beak
- the perigynium has a beak
- Perigynium beak length
- 1.3–2.7 mm
- Perigynium beak orientation
- the beak of the perigynium is curved, or angled out from the perigynium
- Perigynium beak 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
- Up to 0.5 mm
- Perigynium color
- yellow
- Perigynium cross-section
-
- the perigynium is relatively round in cross-section
- the perigynium is trigonous (triangular) in cross-section
- Perigynium hairs
-
- the perigynium has no hairs
- the perigynium is hairy
- Perigynium length
- 4–6.3 mm
- Perigynium nerve number
- At least 10
- Perigynium nerve texture
- the nerves on the perigynium are raised, even after drying the perigynium
- Perigynium nerves lower side
- At least 5
- Perigynium nerves upper side
- At least 5
- Perigynium orientation
- the perigynia are curved or bent downwards or backwards along the axis
- Perigynium puffy
- the perigynium is inflated (there is space between the perigynium and the achene)
- Perigynium shape
-
- the perigynium body is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
- the perigynium body is ovate (egg-shaped)
- Perigynium width
- 1–1.9 mm
- Perigynium winged
- the perigynium has no wings
- Pollen- and seed-producing spikes
- some of the spikes produce perigynia
- Pollen-producing spike length
- 9–22 mm
- Pollen-producing spike number
- 1–2
- Pollen-producing spike peduncle length
- 0.4–9 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
- the carpellate scale awn does not have teeth (it may or may not have hairs)
- Scale color
- red-brown
- Scale length
- 2.3–3.9 mm
- Scale tip
-
- the carpellate scale tip is acute (has a sharp point)
- the carpellate scale tip is obtuse (has a blunt 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 angled outwards, or arched over
- the spikes are oriented vertically or pressed against the axis
- Spikes per stem
- 2-15
- Staminate scale tip
- the staminate scale tip is obtuse (has a blunt point)
- Stigma branching
- the stigmas have three branches
- Top spike
-
- the uppermost spike contains both staminate and carpellate flowers, with the carpellate flowers located below, or intermixed with, the staminate flowers
- the uppermost spike contains only staminate flowers
-
Fruits or seeds
- Achene dimples
- the achene has no folds or dimples
- Achene length
- 1.3–1.7 mm
- Achene width
- 0.9–1.2 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 length to width ratio
- 31–52
- 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
- Leaf sheath bumps
- there are no papillae at the top edge of the leaf sheath
- Leaf sheath color
- the leaf sheath has no pink, red or purple tinting
- 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 a sheath longer than four millimeters
- the lowest bract has no sheath (or a very short sheath up to four millimeters in length)
- Lowest leaf blade width
- 1.6–5.8 mm
- Lowest leaf sheath texture
- the leaf sheath feels smooth (it may have soft hairs)
- stem leaf blade width
- 1.6–5.8 mm
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- meadows or fields
- ridges or ledges
- shores of rivers or lakes
-
Stem, shoot, branch
- Plant height
- 10–75 cm
- Relative stem height
-
- the main stem is equal to or shorter than the leaves
- the main stem is taller 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
Occurs only in wetlands. (Wetland indicator code: OBL)
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.
- Massachusetts
- fairly widespread (S-rank: S4)
- Vermont
- widespread (S-rank: S5)
Native to North America?
Yes
Sometimes confused with
- Carex cryptolepis:
- perigynia 3.5-4.8 mm long, of similar color with the yellow-green carpellate scales, with a smooth beak offset 13-48 degrees from the body (vs. C. flava, with perigynia 4-6.3 mm long, contrasting in color with the red-brown carpellate scales, with a scabrous beak offset mostly 26-72 degrees from the body).
Synonyms
- Carex flava var. fertilis Peck
- Carex flava var. gaspensis Fern.
- Carex laxior (Kükenth.) Mackenzie
Family
Genus
From the dichotomous key of Flora Novae Angliae
27. Carex flava L. N
yellow-green sedge. Carex flava L. var. fertilis Peck; C. flava L. var. gaspensis Fern.; C. laxior (Kükenth.) Mackenzie • CT, MA, ME, NH, RI, VT. Wet meadows, shorelines, and seepy ledges; calciphile.
27×28. Carex flava × Carex viridula → Carex ×ruedtii Kneuck. is a rare sedge hybrid in New England known from MA, ME, NH. It is recognized by its perigynia that are mostly 3.1–4 mm long with a smooth or sparsely serrulate, essentially straight beak, carpellate scales that are brown and contrast with the green perigynia, and upper leaves with ligules (lacking ligules in C. viridula).