Lolium multiflorum Lam.

Italian rye grass

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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

Italian rye grass, a European species, is a very widespread non-native grass found in fields, roadsides and disturbed areas across much of the temperate world. It has been widely planted as a cover crop, forage, and lawns. It can interbreed with its close relative, Lolium perenne (perennial rye-grass). It is distinguished from this species by the comparatively long awns on the spikelets, the rough texture of the inflorescence axis (rachis), and the wider leaves that are rolled (not folded) when still in bud.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Vermont
Leaf blade width
2–13 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
8–31 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
0–10 mm
Leaf ligule length
Up to 4 mm
Anther length
2.5–5 mm
Show All Characteristics
  • Flowers
    Anther length
    2.5–5 mm
    Anther number
    3
    Awn on glume
    the glume has no awn
    Bristles below spikelets
    no
    Floret lower bract texture
    • the lemma is hard and firm
    • the lemma is thin and flexible
    Floret number
    10–22
    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 flat or curved in cross-section
    Glume veins
    • 3
    • 5
    • 7 or more
    Glumes per spikelet
    • 1
    • 2
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis hairs
    the inflorescence axis is rough and feels like sand-paper
    Inflorescence axis orientation
    • the inflorescence axis is arched or curved outward
    • 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
    150–450 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)
    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
    0–10 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 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 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 vein number
    • 5
    • 7 or more
    Lemma vein orientation
    the veins on the lemma stay roughly parallel throughout
    Lower glume length
    0–18 mm
    One or more florets
    there is more than one floret per spikelet
    Palea relative length
    • palea is longer than lemma
    • 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
    Spikelet length
    8–31 mm
    Spikelet number per node
    Up to 1
    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
    • the spikelets are ovate (egg-shaped, widest below the middle with rounded ends) in profile
    Spikelet width
    2–10 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
    5–18 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
    Seed length
    2.5–4 mm
  • Growth form
    Horizontal rooting stem
    no
    Lifespan
    • the plant lives more than two years
    • the plant lives only a single year or less
  • Leaves
    Leaf auricles
    the leaves have auricles
    Leaf blade base
    the leaf is tapered gradually to the base
    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
    Leaf blade length
    10–30 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
    2–13 mm
    Leaf ligule length
    Up to 4 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 color and persistence
    the leaf sheathes are reddish-brown and disintegrate or become shredded in older leaves
    Leaf sheath hairs
    there are no 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
    • 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
    Up to 150 cm
    Stem hairs
    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 most often in non-wetlands, but rarely 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

None

Native to North America?

No

Sometimes Confused With

Lolium perenne:
rachis of the inflorescence smooth on the surface opposite the spikelet, rough only on the angles, spikelets with mostly 5–10 florets, apex of the glume of upper spikelets more or less extending to the tip of the lowest lemma on the same side (vs. L. multiflorum, with the rachis of the inflorescence rough on the surface opposite the spikelet, spikelets with mostly 11–22 florets, and apex of the glume of upper spikelets not reaching the tip of the lowest lemma on the same side).
Lolium temulentum:
glume mostly 7–28 mm long, the body 0.75–1.5 times as tall as the column of florets, plants annual, with 2- to 10-flowered (vs. L. multiflorum, with the glume 3.5–15 mm long, the body 0.25–0.75 times as tall as the column of florets, and plants annual or perennial, with mostly 5- to 22-flowered spikelets).

Synonyms

  • Lolium multiflorum Lam. ssp. italicum (A. Braun) Volk. ex Schinz & R. Keller
  • Lolium perenne L. ssp. multiflorum (Lam.) Husnot
  • Lolium perenne L. var. aristatum Willd.
  • Lolium perenne L. var. multiflorum (Lam.) Parnell

Family

Poaceae

Genus

Lolium

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Information from Dichotomous Key of Flora Novae Angliae

1.  Lolium multiflorum Lam. E

Italian rye grass. Lolium multiflorum Lam. ssp. italicum (A. Braun) Volk. ex Schinz & R. Keller; 
 L. perenne L. var. aristatum Willd.; L. perenne L. ssp. multiflorum (Lam.) Husnot; L. perenne L. var. multiflorum (Lam.) Parnell • CT, MA, ME, NH, VT. Fields, roadsides, seeded areas.