Lolium perenne

Species category

Agricultural, Turf

Common name

perennial ryegrass, Italian ryegrass

Diagnostic characters

Planting unit

CaryopsisCaryopsis:
The single-seeded fruit or grain of the grass family (Poaceae); the fruit wall (pericarp) is united with the seed coat (testa).

Shape

Lanceolate

Size

  • Length 5.5–6.5 mm
  • Width 1.5–1.8 mm
  • Thickness 0.8–1 mm

Color

Light brown

Texture

Smooth and shiny

Lemma

No awnsAwn:
A narrow, bristle-like organ, as on the glumes or lemmas of grasses (Poaceae).
; some nerves on apicalApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
half converging at apexApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
.

Palea

Usually the same length as the lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.
; margins with serrate teeth.

Other structures

RachillaRachilla:
The axis of a spikelet.
is flat or strap-like; callusCallus:
The hard base of grass florets or spikelets, just above the point of disarticulation.
is straight and wide.

Identification notes

This species has no awnsAwn:
A narrow, bristle-like organ, as on the glumes or lemmas of grasses (Poaceae).
. Surface of both lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.
and paleaPalea:
One of the thin bracts of grass floret enclosing the fruit (caryopsis) that is located on the side opposite the embryo.
is smooth and shiny. Sides of the floretFloret:
A small flower in a clustered inflorescence (e.g., sunflower, grasses). In grasses, a floret consists of the lemma, palea, stamens, and pistil.
tend to be parallel. RachillaRachilla:
The axis of a spikelet.
is flat.

Noxious weed seed categories

Not listed

AOSA examination list

Included

More information

For more information, see ISMA fact sheet.

Nomenclature

Family

Poaceae

Valid name

Lolium perenne L.

From Left to Right: 1.   Lolium perenne  ssp.  multiflorum  2.  Lolium perenne  3.  Lolium persicum  4.  Lolium temulentum . Caryopses with a straight and wide callus. 
From Left to Right: 1.  Lolium perenne ssp. multiflorum 2. Lolium perenne 3. Lolium persicum 4. Lolium temulentum. Caryopses with a straight and wide callus. 
 Lolium perenne.  Florets with no awns and shiny palea and lemma surfaces.
Lolium perenne. Florets with no awns and shiny palea and lemma surfaces.