Elymus repens (L.) Gould

creeping wild-rye

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New England Distribution

Adapted from BONAP data

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North America Distribution

Adapted from BONAP data

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Facts About

Creeping wild-rye is a Eurasian grass that has become a seriously invasive weed around the globe. One source states that it is among the world's three most serious weeds, infesting 37 different crops in 65 countries. It is present throughout New England in fields and anthropogenically disturbed sites, but also sometimes in natural habitats such as cobble river shores.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields, shores of rivers or lakes

Characteristics

Habitat
  • terrestrial
  • wetlands
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Leaf blade width
6–10 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
10–27 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
0–10 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
0.25–1.5 mm
Anther length
3–7 mm
Show All Characteristics
  • Flowers
    Anther length
    3–7 mm
    Anther number
    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
    4–7
    Floret types within spikelet
    all the florets within a spikelet are similar
    Glume awn length
    0–3 mm
    Glume keel
    • NA
    • the glume keels are rough or hairy
    Glume relative length
    neither glume is quite as long as all of the florets
    Glume shape
    the glume is V-shaped in cross-section
    Glume veins
    • 3
    • 5
    • 7 or more
    Glumes per spikelet
    2
    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
    50–150 mm
    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
    5–15 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
    0–10 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 cross-section
    the lemma is V-shaped 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 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 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
    8.8–11.4 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
    7–9.5 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
    10–27 mm
    Spikelet number per node
    1–2
    Spikelet pedicel
    the spikelets do not have pedicels
    Spikelet pedicel length
    0 mm
    Spikelet position
    NA
    Spikelet shape
    • the spikelets are elliptic (widest in the middle, tapering to the ends) in profile
    • the spikelets are oblong (rectangular, but with rounded ends) in profile
    Spikelet width
    3–5 mm
    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
    7–12 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 above the middle
    • 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
    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
    • the plant has large or prominent tufts of leaves at the base of the flowering stem
    Leaf 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 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
    6–30 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
    6–10 mm
    Leaf ligule length
    0.25–1.5 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 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
    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
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields
    • shores of rivers or lakes
  • Stem, shoot, branch
    Hairs at nodes
    the stem nodes are hairless or they have very sparse hairs
    Plant height
    50–100 cm
    Stem hairs
    the stem is nearly to completely hairless
    Stem node number
    3–5
    Stem orientation
    the stems are upright
    Stem spacing
    the stems grow singly or a few together (they may form diffuse colonies)

Wetland Status

Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)

New England Distribution and Conservation Status

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.

Massachusetts
unranked (S-rank: SNR)

var. repens

Massachusetts
unranked (S-rank: SNR)

var. vaillantiana

Massachusetts
unranked (S-rank: SNR)

Native to North America?

No

Sometimes Confused With

Thinopyrum pycnanthum:
glumes acute at the apex, unawned or with a tiny mucro to 0.5 mm long (vs. E. repens, with glumes long-acute at the apex, usually with an awn mostly 0.5-4 mm long).
Elymus trachycaulus:
anthers 1-2 mm long and plants cespitose, without rhizomes (vs. E. repens, with anthers 3-7 mm long and plants not cespitose, with rhizomes).

Synonyms

  • Agropyron repens (L.) Gould
  • Elytrigia repens (L.) Desv. ex B.D. Jackson
  • Triticum repens L.

Family

Poaceae

Genus

Elymus

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Information from Dichotomous Key of Flora Novae Angliae

6.  Elymus repens (L.) Gould E

creeping wild-rye. Agropyron repens (L.) Gould; Elytrigia repens (L.) Desv. ex B.D. Jackson; Triticum repens L. • CT, MA, ME, NH, RI, VT; thoughout. Fields, roadsides, areas of cultivation, sometimes colonizing native habitats such as gravel and cobble river shores.