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Elymus hystrix — eastern bottle-brush grass

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Facts

Eastern bottle-brush grass is a common grass of rich, moist floodplain and deciduous forests, where it is often found with sugar maple (Acer saccharum), american basswood (Tilia americana) or white ash (Fraxinus americana), or in dry to moist woodlands and hilly forests with neutral to basic bedrock. There are two varieties with overlapping ranges and two, very rare hyrbids. This grass is unmistakeable for its widely-spaced, spreading, long-awned spikelets arrayed along a long axis.

Habitat

Floodplain (river or stream floodplains), forests, ridges or ledges, woodlands

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Leaf blade width
4–16 mm
Inflorescence branches
there are no branch points between the base of the inflorescence axis and the flowers, or they are not obvious
Spikelet length
10–18 mm
Glume relative length
  • neither glume is quite as long as all of the florets
  • one or both glumes are as long or longer than all of the florets
Awn on glume
  • NA
  • 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
12–47 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
1–3 mm
Anther length
2.5–5 mm
Show all characteristics

  • Flowers

    Anther length
    2.5–5 mm
    Anther number
    3
    Awn on glume
    • NA
    • 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
    1–6
    Floret types within spikelet
    there are at least two distinct forms of florets within one spikelet
    Glume awn length
    0–20 mm
    Glume keel
    NA
    Glume relative length
    • neither glume is quite as long as all of the florets
    • one or both glumes are as long or longer than all of the florets
    Glume shape
    the glume is flat or curved in cross-section
    Glume veins
    0
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis hairs
    • the inflorescence axis is hairy but not rough or sand-papery feeling
    • the inflorescence axis is rough and feels like sand-paper
    • the inflorescence axis is smooth and has no hairs
    Inflorescence axis orientation
    the inflorescence axis is straight
    Inflorescence branch length
    0 cm
    Inflorescence branch roughness
    NA
    Inflorescence branches
    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
    0
    Inflorescence crowding
    NA
    Inflorescence length
    70–200 mm
    Inflorescence length to width ratio
    1.8–2.9
    Inflorescence type (general)
    the inflorescence is a spike, or is spike-like, lacking obvious branches
    Inflorescence type (specific)
    the inflorescence is a spike (a long unbranched stem with flowers along it that lack stalks)
    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 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
    12–47 mm
    Lemma awn number
    the lemma has one awn on it
    Lemma awn orientation
    the awn of the lemma is straight
    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 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 length
    0–20 mm
    Lower glume relative length
    • NA
    • the lower glume is nearly as long, or as long as, the upper glume
    • the lower glume is one third or less as long as the upper glume
    • the lower glume is one third to three quarters as long as the upper glume
    One or more florets
    there is more than one floret per spikelet
    Palea length
    7–11 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 no 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
    • the spikelet breaks off below the glumes
    Spikelet length
    10–18 mm
    Spikelet number per node
    Up to 3
    Spikelet pedicel
    the spikelets do not have pedicels
    Spikelet pedicel length
    0 mm
    Spikelet position
    NA
    Spikelet shape
    the spikelets are lanceolate (lance-shaped, widest below the middle and tapering narrowly to the ends) 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 length
    0–20 mm
    Upper glume shape
    • NA
    • 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
    Rhizomes
    no
    Roots
    there are only slender roots on the plant

  • 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 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 texture
    • the leaf blade is rough and sandpapery
    • the leaf blade is smooth, or it may have soft hairs
    Leaf blade width
    4–16 mm
    Leaf ligule length
    1–3 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 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
    Orientation of topmost leaf
    the flag leaf is held outward at more than a 45 degree angle from the stem, or it curves downwards from the horizontal

  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • forests
    • ridges or ledges
    • river or stream floodplains
    • woodlands

  • Stem, shoot, branch

    Hairs at nodes
    the stem nodes are hairless or they have very sparse hairs
    Plant height
    50–140 cm
    Stem node number
    4–8
    Stem orientation
    • the stems are upright
    • 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
present
Rhode Island
present
Vermont
present

Conservation status

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

Maine
uncommon (S-rank: S3), special concern (code: SC)

var. bigeloviana

Massachusetts
unranked (S-rank: SNR)
New Hampshire
uncommon (S-rank: S3), W (code: W)
Rhode Island
concern (code: C)

var. hystrix

Massachusetts
widespread (S-rank: S5)
New Hampshire
uncommon (S-rank: S3), W (code: W)

Subspecies and varieties

Variety bigeloviana is known from CT, MA, ME, NH, RI, VT. It appears to be most common in mesic soils. Variety hystrix is known from CT, MA, ME, NH, VT.

From Flora Novae Angliae dichotomous key

4.  Elymus hystrix L. N

eastern bottle-brush grass.  4a. Hystrix patula Moench var. bigeloviana (Fern.) Deam;  
4b. Hystrix hystrix (L.) Millsp.; H. patula Moench • CT, MA, ME, NH, RI, VT. Rich, mesic soils of 
high-terrace floodplain forests and deciduous forests, often associated with Acer saccharum, Tilia americana, and/or Fraxinus americana; also in dry-mesic woodlands and forests on 
hills and ridges underlaid by circumneutral to basic bedrock.

1a.  Lemmas appressed-puberulent to strigose 
 … 4a. E. hystrix var. bigeloviana (Fern.) Bowden

1b.  Lemmas glabrous or scabrous … 4b. E. hystrix var. hystrix

Variety bigeloviana is known from CT, MA, ME, NH, RI, VT. It appears to be most common in mesic soils. Variety hystrix is known from CT, MA, ME, NH, VT.

3×4. Elymus glabriflorus × Elymus hystrix → This extremely rare grass hybrid is currently known within New England 
from a single hill in New Haven County, CT, where it occurs with both parents. It is recognized by the intermediate nature of the glume development, spike width, 
and spikelet orientation.

4×7. Elymus hystrix × Elymus riparius → This very rare wild-rye hybrid is known from VT. It generally resembles Elymus riparius with a large, arching spike. However, the spike internodes are 6–7 mm long (rather than 3–5 mm long), the glumes range in development from nearly absent or merely slender bristles (as in E. hystrix) to fully developed (as in E. riparius), and the spikelets are more loosely spreading than in typical E. riparius.

Native to North America?

Yes

Synonyms

  • Hystrix hystrix (L.) Millsp.
  • Hystrix patula Moench

Family

Poaceae

Genus

Elymus