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• Poaceae
• Poaceae Group 5
• Elymus
• Elymus repens

Elymus repens — creeping wild-rye

Facts

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

• 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

From the dichotomous key of Flora Novae Angliae