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- Dichotomous Key
- Poaceae
- Poaceae Group 5
- Hordeum
- 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.
Found this plant? Take a photo and post a sighting.
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.
ssp. leporinum
- Massachusetts
- not applicable (S-rank: SNA)
Subspecies and varieties
Our subspecies is Hordeum murinum L. ssp. leporinum.
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.
Native to North America?
No
Sometimes confused with
- Hordeum pusillum:
- glumes of the central spikelet of each triad with scabrous margins; auricles absent or poorly developed and very short (vs. H. murinum, with glumes of the central spikelet of each triad with ciliate margins, and auricles present at the summit of most leaf sheaths, well-developed, up to 8 mm long).
Synonyms
- Critesion murinum (L.) A. Löve var. leporinum (Link) A. Löve
- Hordeum leporinum Link