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- True grasses
- Hordeum murinum
Hordeum murinum — mouse barley
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Facts
Mouse barley is a non-native grass that is occasionally found in Connecticut, Massachusetts and Maine.
Habitat
Anthropogenic (man-made or disturbed habitats), meadows and fields
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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Characteristics
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- Leaf blade width
- 2–5 mm
- Inflorescence branches
-
- the flowers are attached to branches rather than to the main axis of the inflorescence
- there are no branch points between the base of the inflorescence axis and the flowers, or they are not obvious
- Glume relative length
- neither glume is quite as long as all of the florets
- Awn on glume
- the glume has an awn
- One or more florets
- there is one floret per spikelet
- Lemma awn length
- 5–50 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
- there are no hairs on the surface of the leaf sheath
- Leaf ligule length
- 1–4 mm
- Anther length
- 1.2–3.2 mm
-
Flowers
- Anther length
- 1.2–3.2 mm
- Anther number
- Up to 3
- Awn on glume
- the glume has an awn
- Bristles below spikelets
- no
- Floret lower bract texture
- the lemma is thin and flexible
- Floret number
- 1
- Floret types within spikelet
- there are at least two distinct forms of florets within one spikelet
- Glume awn length
- 11–25 mm
- Glume keel
- NA
- Glume relative length
- neither glume is quite as long as all of the florets
- Glume shape
-
- the glume is V-shaped in cross-section
- the glume is flat or curved in cross-section
- Glume veins
-
- 1
- 3
- 5
- Glumes per spikelet
- 2
- Inflorescence axis orientation
-
- the inflorescence axis is arched or curved outward
- the inflorescence axis is straight
- Inflorescence branches
-
- the flowers are attached to branches rather than to the main axis of the inflorescence
- there are no branch points between the base of the inflorescence axis and the flowers, or they are not obvious
- Inflorescence branches coming off the lowest stem node
- Up to 2
- Inflorescence crowding
- NA
- Inflorescence length
- 30–80 mm
- Inflorescence length to width ratio
- 4.3–5
- Inflorescence type (general)
-
- the inflorescence is a spike, or is spike-like, lacking obvious branches
- the spikelets are borne on stalks or on branches
- Inflorescence type (specific)
- the inflorescence has pairs (or trios) of spikelets, but with one always either missing a stalk or on a shorter stalk than the other
- Inforescence position
- the spikelets are mainly carried at the end of the stem
- Lemma awn base
- the awn is attached right at the tip of the lemma
- Lemma awn coiled
- the lemma awn is straight or twisted, but not coiled one half turn
- Lemma awn length
- 5–50 mm
- Lemma awn number
- the lemma has one awn on it
- Lemma awn orientation
-
- the awn of the lemma is straight
- the awn of the lemma on dried or older plants is curved or bent outwards
- Lemma cross-section
- the lemma is flat or rounded if you cut across the midpoint
- Lemma keel hairs
- NA
- 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 tip shape
- the lemma tip tapers to a long narrow point (it may or may not also have an awn or teeth at the tip)
- Lemma vein number
- 5
- Lemma vein orientation
- the veins on the lemma stay roughly parallel throughout
- Lower glume relative length
- the lower glume is nearly as long, or as long as, the upper glume
- One or more florets
- there is one floret per spikelet
- Palea length
- 8–15 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 length
- 2.5–6.5 mm
- Spikelet axis tip
- there is an extension of the spikelet axis beyond the tip of the spikelet
- Spikelet disintegration
- the spikelet breaks off below the glumes
- Spikelet pedicel
-
- the spikelets do not have pedicels
- the spikelets have pedicels
- Spikelet pedicel length
- 0–1 mm
- Spikelet position
-
- NA
- the spikelets emerge mainly from the upper halves of the inflorescence branches
- Spikelet shape
- the spikelets are obovate (egg-shaped but with the widest point above the middle) in profile
- Spikelets per panicle branch
- 0
- 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 relative length
- the upper glume is up to one half as long as the lowest lemma
- Upper glume shape
- the upper glume is widest at or below the middle
-
Fruits or seeds
- Groove on seed
- the caryopsis has a groove running most of its length
- Seed length
- 4–5 mm
-
Growth form
- Lifespan
- the plant lives only a single year or less
-
Leaves
- Leaf auricles
-
- the leaves do not have auricles
- the leaves have auricles
- Leaf blade cross-section
-
- the leaf blade is clearly folded or rolled inwards
- 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
- Up to 28 cm
- Leaf blade texture
-
- the leaf blade is rough and sandpapery
- the leaf blade is smooth, or it may have soft hairs
- Leaf blade width
- 2–5 mm
- Leaf ligule length
- 1–4 mm
- Leaf ligule type
- the leaf ligule is in the form of a membrane
- 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 hair type
-
- there are hairs on the surface of the leaf sheath, but the hairs do not have blisters at their bases
- there are no hairs on the surface of the leaf sheath
- 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
- New England state
-
- Connecticut
- Maine
- Massachusetts
- Specific habitat
-
- man-made or disturbed habitats
- meadows or fields
-
Stem, shoot, branch
- Hairs at nodes
- the stem nodes are hairless or they have very sparse hairs
- Plant height
- 30–110 cm
- Stem hairs
- the stem is nearly to completely hairless
- Stem orientation
-
- the stems are upright
- the stems trail along the ground or on other plants through most or all of their length
- the stems trail at the base, but turn upwards at the tips
- Stem spacing
- the stems grow close together in compact clusters or tufts
Wetland status
Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)
In New England
Distribution
- Connecticut
- present
- Maine
- present
- 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
- unranked (S-rank: SNR)
ssp. leporinum
- Massachusetts
- unranked (S-rank: SNR)
From Flora Novae Angliae dichotomous key
3. Hordeum murinum L. ssp. leporinum (Link) Arcang. E
mouse barley. Critesion murinum (L.) A. Löve var. leporinum (Link) A. Löve; Hordeum leporinum Link • CT, MA, ME. Roadsides, fields, disturbed soil.