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- Dichotomous Key
- Poaceae
- Poaceae Group 4
- Bromus
- Bromus inermis
Bromus inermis — smooth brome
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Facts
Smooth brome is a Eurasian species introduced to North America, where it has been used extensively for habitat rehabilitation and as a forage plant.
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
- Vermont
- Leaf blade width
- 5–15 mm
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Spikelet length
- 20–40 mm
- Glume relative length
- neither glume is quite as long as all of the florets
- Awn on glume
- the glume has no awn
- One or more florets
- there is more than one floret per spikelet
- Lemma awn length
- 0–3 mm
- Leaf sheath hair type
- there are no hairs on the surface of the leaf sheath
- Leaf ligule length
- 0.5–3 mm
- Anther length
- 3.5–6 mm
-
Flowers
- Anther length
- 3.5–6 mm
- Anther number
- 2–3
- Awn on glume
- 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
- 0 mm
- Glume keel
- the glume keels are smooth and hairless
- 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
- Glumes per spikelet
- 2
- Inflorescence arrangement
- the spikelets are uniform
- Inflorescence axis orientation
- the inflorescence axis is straight
- Inflorescence branch roughness
- the inflorescence branches are somewhat to very rough
- Inflorescence branches
- the flowers are attached to branches rather than to the main axis of the inflorescence
- Inflorescence branches coming off the lowest stem node
- 4–10
- Inflorescence crowding
- the panicle is somewhat to very spread out, with clearly-evident branches
- Inflorescence length
- 100–200 mm
- Inflorescence length to width ratio
- 2.5–2.9
- Inflorescence type (general)
- 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
- 40–70 mm
- Inforescence position
- the spikelets are mainly carried at the end of the stem
- Lemma awn base
- the awn is attached at the upper half of the lemma
- Lemma awn coiled
- the lemma awn is straight or twisted, but not coiled one half turn
- Lemma awn length
- 0–3 mm
- Lemma awn number
-
- the lemma has no awn
- the lemma has one awn on it
- Lemma awn orientation
- the awn of the lemma is straight
- 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 is hairless between the veins
- Lemma keel hairs
-
- the keel of the lemma is hairless
- the keel of the lemma is rough, or has fine hairs
- 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 broad point (it may or may not also have an awn or teeth at the tip)
- 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
-
- 3
- 5
- Lemma vein orientation
- the veins on the lemma come together near the tip
- Lower glume length
- 4–9 mm
- Lower glume relative length
- the lower glume is nearly as long, or as long as, the upper glume
- One or more florets
- there is more than one floret per spikelet
- Palea length
- 8–9 mm
- 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
- 20–40 mm
- Spikelet number per node
- 0
- Spikelet pedicel
- the spikelets have pedicels
- Spikelet shape
-
- the spikelets are elliptic (widest in the middle, tapering to the ends) in profile
- the spikelets are lanceolate (lance-shaped, widest below the middle and tapering narrowly to the ends) in profile
- Spikelet width
- 3–6 mm
- 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
- 5–10 mm
- Upper glume relative length
- the upper glume is more than 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
- 8–9 mm
-
Growth form
- Horizontal rooting stem
- no
- Lifespan
- the plant lives more than two years
- Rhizomes
- yes
- Roots
- the plant has rhizomes (horizontal underground stem with roots growing from it)
-
Leaves
- Basal leaves
- the plant has few or no leaves coming from the base of the flowering stem
- Leaf auricles
-
- the leaves do not have auricles
- the leaves have auricles
- Leaf basal lobe hairy
- the lobes at the base of the leaf blades are hairless
- 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
- 11–42 cm
- Leaf blade texture
- the leaf blade is rough and sandpapery
- Leaf blade width
- 5–15 mm
- Leaf ligule length
- 0.5–3 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 no hairs on the surface of the leaf sheath
- Leaf sheath hairs
- there are no hairs on the surface of the leaf sheath
-
Place
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- 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
- 50–130 cm
- Stem hairs
-
- the stem has hairs on it
- the stem is nearly to completely hairless
- Stem node number
- 2–6
- Stem orientation
- the stems are upright
- Stem spacing
- the stems grow singly or a few together (they may form diffuse colonies)
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
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
ssp. inermis
- Massachusetts
- not applicable (S-rank: SNA)
Subspecies and varieties
Our subspecies is Bromus inermis Leyss. ssp. inermis.
From Flora Novae Angliae dichotomous key
7. Bromus inermis Leyss. ssp. inermis E
smooth brome. Bromopsis inermis (Leyss.) Holub • CT, MA, ME, NH, RI, VT. Fields, roadsides, disturbed soil. Collections of this species with shortly awned lemmas are responsible for the reports of Bromus pumpellianus Scribn. in New England. These collections lack the spikelet and leaf pubescence of the latter species (i.e., they are merely part of the variation displayed by B. inermis).