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- Section Ceratocystis
- Carex flava
Carex flava — yellow-green sedge
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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
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.
Characteristics
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- 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 blade width
- 1.6–5.8 mm
- 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)
-
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)
In New England
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
- unranked (S-rank: SNR)
- Vermont
- widespread (S-rank: S5)
From Flora Novae Angliae dichotomous key
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).
Native to North America?
Yes
Sometimes confused with
- Carex cryptolepis:
- scales subtending perigynia yellow-green, of similar color as the perigynia, and perigynium beak without minute teeth (vs. C. flava, with scales subtending perigynia red-brown, contrasting with the color of the perigynia, and perigynium beak with minute teeth along the margin).
Synonyms
- Carex flava var. fertilis Peck
- Carex flava var. gaspensis Fern.
- Carex laxior (Kükenth.) Mackenzie