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• Grass-like plants
• True grasses
• Hordeum murinum

Hordeum murinum — mouse barley

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

Characteristics

• 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)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae