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- Poaceae Group 4
- Bromus
- Bromus hordeaceus
Bromus hordeaceus — soft brome
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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
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
- 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
-
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.