Your help is appreciated. We depend on donations to help keep this site free and up to date for you. Can you please help us?

Donate

Native Plant Trust: Go Botany Discover thousands of New England plants

Bromus hordeaceus — soft brome

Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.

Facts

Soft brome is native to Europe, northern Africa, and parts of Asia. It is introduced in North and South America and Australia. There are three subspecies in New England, two of which are less common and found only in southern New England.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields

New England distribution

Adapted from BONAP data

Found this plant? Take a photo and post a sighting.

North America distribution

Adapted from BONAP data

enlarge

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
Leaf blade width
1–4 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
Spikelet length
11–23 mm
Glume relative length
neither glume is quite as long as all of the florets
Awn on glume
  • the glume has an awn
  • the glume has no awn
One or more florets
there is more than one floret per spikelet
Lemma awn length
6–8 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
1–1.5 mm
Anther length
0.6–1.5 mm
Show all characteristics
  • Flowers

    Anther length
    0.6–1.5 mm
    Anther number
    2–3
    Awn on glume
    • the glume has an awn
    • the glume has no awn
    Bristles below spikelets
    no
    Floret lower bract texture
    the lemma is thin and flexible
    Floret number
    5–10
    Floret types within spikelet
    all the florets within a spikelet are similar
    Glume awn length
    At least 0 mm
    Glume relative length
    neither glume is quite as long as all of the florets
    Glume veins
    • 3
    • 5
    • 7 or more
    Glumes per spikelet
    2
    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
    • there are no branch points between the base of the inflorescence axis and the flowers, or they are not obvious
    Inflorescence crowding
    the panicle is somewhat to very congested (crowded), and the branches may not be clearly seen without close inspection
    Inflorescence length
    30–100 mm
    Inflorescence length to width ratio
    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 is branched, and the branches do NOT both grow from the same side of the plant AND look like spikes
    Inflorescence width
    10–20 mm
    Inforescence position
    the spikelets are mainly carried at the end of the stem
    Lemma awn coiled
    the lemma awn is straight or twisted, but not coiled one half turn
    Lemma awn length
    6–8 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 base hair length
    0 mm
    Lemma base hairs
    the lemma is hairless or feels just a tiny bit rough at the base
    Lemma cross-section
    the lemma is flat or rounded if you cut across the midpoint
    Lemma hairs
    • the lemma has fine hairs between the veins
    • the lemma is hairless between the veins
    Lemma keel hairs
    NA
    Lemma marginal vein hairs
    • the marginal vein of the lemma has fine hairs on it
    • 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 split into two or more points
    Lemma tip shape
    the lemma tip tapers to a narrow point (it may or may not also have an awn or teeth at the tip)
    Lemma vein number
    7 or more
    Lemma vein orientation
    the veins on the lemma come together near the tip
    Lower glume length
    5–7 mm
    One or more florets
    there is more than one floret per spikelet
    Palea relative length
    palea is one half to fully as long as lemma
    Reproductive system
    all the flowers on the plant have both carpels and stamens (synoecious)
    Spikelet axis tip
    there is an extension of the spikelet axis beyond the tip of the spikelet
    Spikelet disintegration
    the spikelet breaks off above the glumes, so that after the florets fall off, the glumes remain
    Spikelet length
    11–23 mm
    Spikelet number per node
    Up to 0
    Spikelet pedicel
    the spikelets have pedicels
    Spikelet shape
    the spikelets are lanceolate (lance-shaped, widest below the middle and tapering narrowly to the ends) in profile
    Spikelet width
    4–6 mm
    Spikelets per panicle branch
    At least 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 length
    6.5–8 mm
    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
  • Growth form

    Horizontal rooting stem
    no
    Lifespan
    • the plant lives more than two years
    • the plant lives only a single year or less
    Rhizomes
    no
    Roots
    there are only slender roots on the plant
  • Leaves

    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
    2–19 cm
    Leaf blade width
    1–4 mm
    Leaf ligule length
    1–1.5 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 fused together and form a closed tube except (possibly) at the very top
    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
    Orientation of topmost leaf
    the flag leaf is held upright, or at less than a 45 degree angle out from the stem
  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields
  • Stem, shoot, branch

    Hairs at nodes
    the stem nodes have hairs that stand out at a shallow angle, or they curve downwards
    Plant height
    3–70 cm
    Stem hairs
    • the stem has hairs on it
    • 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
    Stem spacing
    the stems grow close together in compact clusters or tufts

Wetland status

Occurs only in non-wetlands. (Wetland indicator code: UPL)

In New England

Distribution

Connecticut
present
Maine
present
Massachusetts
present
New Hampshire
present
Rhode Island
present
Vermont
absent

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

ssp. hordeaceus

Massachusetts
not applicable (S-rank: SNA)

ssp. pseudothominei

Massachusetts
not applicable (S-rank: SNA)

ssp. thominei

Massachusetts
not applicable (S-rank: SNA)

Subspecies and varieties

Subspecies thominei is known from MA, RI. Its lemmas are 6.5–7.5 mm long and vary from glabrous to pubescent. Subspecies hordeaceus is known from CT, MA, ME, NH, RI. Subspecies pseudothominei is known from CT, MA.

From Flora Novae Angliae dichotomous key

6.  Bromus hordeaceus L. E

soft brome. 6a. Bromus thominei Hardouin; 6b. Bromus mollis L.; 6c. Bromus mollis L. var. leiostachys Hartman • CT, MA, ME, NH, RI. Fields, roadsides, disturbed soil.

1a.  Inflorescence often reduced to 1 or 2 spikelets; reproductive stems slender, 2–16 cm tall; awns sometimes divaricate in fruit 
 … 6a. B. hordeaceus ssp. thominei  (Hardouin) Mair e in Emberger & Maire

1b.  Inflorescence usually not reduced to 1 or 2 spikelets (except in depauperate forms of 
 B. hordeaceus ssp. hordeaceus) [Fig. 197]; reproductive stems medium to stout, (3–) 10–70 cm tall; awns straight and erect

2a.  Lemmas 8–11 mm long, usually pubescent, the margins with an obscurely angled bend where the lemma begins to taper toward the apex from its widest point; caryopsis shorter than the palea … 6b. B. hordeaceus ssp. hordeaceus

2b.  Lemmas 6.5–8 mm long, usually glabrous, the margins with an abrupt bend where the lemma begins to taper toward the apex from its widest point; caryopsis usually as long as the palea … 6c. B. hordeaceus ssp. pseudothominei (P. Sm.) H. Scholz

Subspecies thominei is known from MA, RI. Its lemmas are 6.5–7.5 mm long and vary from glabrous to pubescent. Subspecies hordeaceus is known from CT, MA, ME, NH, RI. Subspecies pseudothominei is known from CT, MA.

Native to North America?

No

Sometimes confused with

Bromus commutatus:
lemmas 1.7-2.6 mm wide, veined, but the veins not prominently raised, and panicles mostly 7-16 cm tall (vs. B. hordeaceus, with lemmas 3-5 mm wide, with prominently raised veins, and panicles mostly 3-10 cm tall).
Bromus lepidus:
lemmas 4.5-6.5 mm long, the margins with a sharp bend where the lemma begins to taper toward the apex from its widest point, and caryopsis longer than its associated palea (vs. B. hordeaceous, with lemmas 6.5-11 mm long, the margins rounded or with a bluntly angled bend where the lemma begins to taper toward the apex from its widest point, and caryopsis as long as or shorter than its associated palea).

Synonyms

  • Bromus mollis L.

Family

Poaceae

Genus

Bromus