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- Dichanthelium scabriusculum
Dichanthelium scabriusculum — tall swamp rosette-panicgrass
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Facts
Tall swamp rosette-panicgrass is native to southern and eastern North America, reaching the limit of its range in New England where it is rare. It inhabits sandy roadsides and rights of way, as well as boggy or rocky streamsides in Connecticut, Massachusetts and Rhode Island.
Habitat
Anthropogenic (man-made or disturbed habitats), bogs, floodplain (river or stream floodplains), grassland
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
- Massachusetts
- Rhode Island
- Leaf blade width
- 7–15 mm
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Spikelet length
- 2.2–2.8 mm
- Glume relative length
- one or both glumes are as long or longer than all of the florets
- Awn on glume
- the glume has no awn
- One or more florets
-
- there is more than one floret per spikelet
- there is one floret per spikelet
- Lemma awn length
- 0 mm
- Leaf sheath hair type
- there are hairs on the surface of the leaf sheath, but the hairs do not have blisters at their bases
- Leaf ligule length
- 0.5–1.2 mm
-
Flowers
- Anther number
- 0–3
- Awn on glume
- the glume has no awn
- Bristles below spikelets
- no
- Floret lower bract texture
- the lemma is hard and firm
- Floret number
- 1–2
- Floret types within spikelet
-
- NA
- there are at least two distinct forms of florets within one spikelet
- Glume relative length
- one or both glumes are as long or longer than all of the florets
- Glume shape
- the glume is flat or curved in cross-section
- Glume veins
-
- 1
- 3
- 5
- 7 or more
- Inflorescence arrangement
- the spikelets are uniform
- Inflorescence axis orientation
- the inflorescence axis is straight
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Inflorescence length
- 100–210 mm
- Inflorescence type (general)
- the spikelets are borne on stalks or on branches
- Inflorescence type (specific)
- the inflorescence is branched, and the branches do NOT both grow from the same side of the plant AND look like spikes
- Lemma awn base
- NA
- Lemma awn coiled
- NA
- Lemma awn length
- 0 mm
- Lemma awn number
- the lemma has no awn
- Lemma awn orientation
- NA
- Lemma cross-section
- the lemma is flat or rounded if you cut across the midpoint
- Lemma surface
- the surface of the lemma is relatively smooth (not counting any longitudinal veins or hairs)
- Lemma tip
- the lemma tip is a simple point, with or without an awn (long narrow extension ending in a point)
- Lemma vein number
-
- 3
- 5
- 7 or more
- One or more florets
-
- there is more than one floret per spikelet
- there is one floret per spikelet
- Palea relative length
- palea is one half to fully as long as lemma
- Spikelet axis tip
- there is no extension of the spikelet axis beyond the tip of the spikelet
- Spikelet length
- 2.2–2.8 mm
- Spikelets spiny
- the spikelets do not appear spiny
- Upper glume shape
- the upper glume is widest at or below the middle
-
Growth form
- Lifespan
- the plant lives more than two years
-
Leaves
- Basal leaves
- the plant has large or prominent tufts of leaves at the base of the flowering stem
- Leaf auricles
- the leaves do not have auricles
- Leaf blade base
- the leaf blade cuts in abruptly to the narrower base, or has rounded lobes on either side of the base (heart-shaped)
- Leaf blade width
- 7–15 mm
- Leaf ligule length
- 0.5–1.2 mm
- Leaf ligule type
- the leaf ligule is in the form of a membrane with fine hairs
- Leaf sheath closed around stem
- the margins of the leaf sheath are overlapping and not fused together except in the basal half (or less)
- Leaf sheath hair type
- there are hairs on the surface of the leaf sheath, but the hairs do not have blisters at their bases
- Leaf sheath hairs
- there are hairs on the surface of the leaf sheath
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Massachusetts
- Rhode Island
- Specific habitat
-
- bogs
- grasslands
- man-made or disturbed habitats
- river or stream floodplains
-
Stem, shoot, branch
- 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
- absent
- Massachusetts
- present
- 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.
- Connecticut
- extremely rare (S-rank: S1), endangered (code: E)
- Massachusetts
- extremely rare (S-rank: S1), threatened (code: T)
- Rhode Island
- historical (S-rank: SH), state historical (code: SH)
From Flora Novae Angliae dichotomous key
12. Dichanthelium scabriusculum (Ell.) Gould & C.A. Clark NC
tall swamp rosette-panicgrass. Panicum aculeatum A.S. Hitchc. & Chase; Panicum scabriusculum Ell. • CT, MA, RI. Dry, sandy roadsides, grasslands, and open rights-of-way, mesic to hydric, rocky or boggy soils adjacent to streams.
Native to North America?
Yes
Sometimes confused with
- Dichanthelium clandestinum:
- leaf blades 15-30 mm wide, flat to the tip, and upper glume and lower lemma of chasmogamous panicles obtuse to subacute at the apex (vs. C. scabriusculum, with leaf blades 7-15 mm wide, tapering to an involute tip, and upper glume and lower lemma of chasmogamous panicles acute to long-acute at the apex).
Synonyms
- Panicum aculeatum A.S. Hitchc. & Chase
- Panicum scabriusculum Ell.