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- True grasses
- Panicum virgatum
Panicum virgatum — switch panicgrass
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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
Switch panicgrass is a North American native perennial drought-tolerant grass that is a palatable forage grass and is planted domestically and worldwide for range and wildlife habitat improvement. It is one of the main species being considered as a biofuel crop, but calculations of carbon emissions savings need to include the effects of widespread land-use conversion if this species begins to be widely grown for biofuels.
Habitat
Anthropogenic (man-made or disturbed habitats), brackish or salt marshes and flats, marshes, meadows and fields, shores of rivers or lakes, wetland margins (edges of wetlands)
Characteristics
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Leaf blade width
- 2–15 mm
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Spikelet length
- 2.5–8 mm
- Glume relative length
- 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 ligule length
- 2–6 mm
-
Flowers
- Anther number
- 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
- 2
- Floret types within spikelet
- there are at least two distinct forms of florets within one spikelet
- Glume awn length
- 0 mm
- Glume keel
- the glume keels are smooth and hairless
- Glume relative length
- 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
-
- 5
- 7 or more
- Glumes per spikelet
- 2
- Inflorescence arrangement
- the spikelets are uniform
- Inflorescence axis orientation
- the inflorescence axis is straight
- Inflorescence branch roughness
- the inflorescence branches are somewhat to very rough
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Inflorescence crowding
- the panicle is somewhat to very spread out, with clearly-evident branches
- Inflorescence length
- 100–550 mm
- Inflorescence length to width ratio
- 2.5–2.8
- 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
- Inflorescence width
- 40–200 mm
- Inforescence position
- the spikelets are mainly carried at the end of the stem
- 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 base hair length
- 0 mm
- Lemma base hairs
- NA
- Lemma base length
- 0 mm
- Lemma cross-section
- the lemma is flat or rounded if you cut across the midpoint
- Lemma hairs
- the lemma is hairless between the veins
- Lemma keel hairs
- the keel of the lemma is hairless
- Lemma marginal vein hairs
- the marginal vein of the lemma is hairless
- 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
- Lower glume length
- 1.8–3.2 mm
- Lower glume relative length
- the lower glume is one third to three quarters as long as the upper glume
- One or more florets
-
- there is more than one floret per spikelet
- there is one floret per spikelet
- Palea length
- 3–3.5 mm
- Palea relative length
- palea is one half to fully as long as lemma
- Reproductive system
- some flowers on the plant have both carpels and stamens, while other flowers have only one type of reproductive organ (polygamous)
- Spikelet axis tip
- there is no extension of the spikelet axis beyond the tip of the spikelet
- Spikelet disintegration
- the spikelet breaks off below the glumes
- Spikelet length
- 2.5–8 mm
- Spikelet number per node
- 0
- Spikelet pedicel
- the spikelets have pedicels
- Spikelet pedicel length
- 0.5–20 mm
- Spikelet shape
-
- the spikelets are lanceolate (lance-shaped, widest below the middle and tapering narrowly to the ends) in profile
- the spikelets are ovate (egg-shaped, widest below the middle with rounded ends) in profile
- Spikelet width
- 1.2–2.5 mm
- Spikelets spiny
- the spikelets do not appear spiny
- Tip of glume
- the tip of the glume is not divided (though it may have an awn on it)
- Upper glume length
- 2.8–8 mm
- Upper glume relative length
- the upper glume is more than one half as long as the lowest lemma
- Upper glume shape
- the upper glume is widest at or below the middle
-
Fruits or seeds
- Seed length
- 2–3 mm
-
Growth form
- Horizontal rooting stem
- no
- Lifespan
- the plant lives more than two years
- Rhizomes
- yes
- Roots
- the plant has rhizomes (horizontal underground stem with roots growing from it)
-
Leaves
- Basal leaves
- the plant has few or no leaves coming from the base of the flowering stem
- Leaf auricles
- the leaves do not have auricles
- Leaf blade base
- the leaf is tapered gradually to the base
- Leaf blade cross-section
- the leaf blade is more or less flat in cross-section, or slightly folded or rolled inwards
- Leaf blade hairs
-
- the leaf blade is hairless, but it may have tiny prickles that give it a sand-papery feel
- the leaf blade is hairy
- Leaf blade length
- 10–60 cm
- Leaf blade texture
- the leaf blade is rough and sandpapery
- Leaf blade width
- 2–15 mm
- Leaf ligule length
- 2–6 mm
- Leaf ligule type
- the leaf ligule is in the form of a membrane with fine hairs
- Leaf margin glands
- there are no glands along the edges of the leaf blade
- 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 hairs
-
- there are hairs on the surface of the leaf sheath
- there are no hairs on the surface of the leaf sheath
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- brackish or salt marshes and flats
- edges of wetlands
- man-made or disturbed habitats
- marshes
- meadows or fields
- shores of rivers or lakes
-
Stem, shoot, branch
- Hairs at nodes
- the stem nodes are hairless or they have very sparse hairs
- Plant height
- 40–300 cm
- Stem hairs
- the stem is nearly to completely hairless
- Stem orientation
-
- the stems are upright
- the stems trail at the base, but turn upwards at the tips
- Stem spacing
-
- the stems grow close together in compact clusters or tufts
- the stems grow singly or a few together (they may form diffuse colonies)
- Stem thickness at base
- 3–5 mm
Wetland status
Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)
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
- unranked (S-rank: SNR)
- Vermont
- uncommon (S-rank: S3)
var. spissum
- Massachusetts
- unranked (S-rank: SNR)
var. virgatum
- Massachusetts
- unranked (S-rank: SNR)
Native to North America?
Yes
Synonyms
- Panicum virgatum var. cubense Griseb.
- Panicum virgatum var. spissum Linder
Family
Genus
From the dichotomous key of Flora Novae Angliae
9. Panicum virgatum L. N
switch panicgrass. Panicum virgatum L. var. cubense Griseb.; P. virgatum L. var. spissum Linder • CT, MA, ME, NH, RI, VT. Fields, roadsides, pond shores, railroads, upper edge of saline to brackish marshes.