Poa annua

Species category

Turf

Common name

annual bluegrass, walkgrass

Diagnostic characters

Planting unit

FloretFloret:
A small flower in a clustered inflorescence (e.g., sunflower, grasses). In grasses, a floret consists of the lemma, palea, stamens, and pistil.

Shape

Lanceolate and rough

Size

  • Length 2–3.1 mm
  • Width 0.5–0.8 mm
  • Thickness 0.8–1 mm

Color

Brown

Texture

Hairs long and dense on lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.
nerves, paleaPalea:
One of the thin bracts of grass floret enclosing the fruit (caryopsis) that is located on the side opposite the embryo.
margins and callusCallus:
The hard base of grass florets or spikelets, just above the point of disarticulation.

Lemma

Long-pointed, thin, and tends to wrinkle; adheres to caryopsisCaryopsis:
The single-seeded fruit or grain of the grass family (Poaceae); the fruit wall (pericarp) is united with the seed coat (testa).
.

Palea

Thin and wrinkled

Other structures

RachillaRachilla:
The axis of a spikelet.
is strong and protruding.

Identification notes

FloretFloret:
A small flower in a clustered inflorescence (e.g., sunflower, grasses). In grasses, a floret consists of the lemma, palea, stamens, and pistil.
rather woolly with fiber.

Noxious weed seed categories

State Noxious Weed: Arizona, Alaska, Connecticut, Delaware, D.C., Florida, Kentucky, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, South Dakota, Tennessee, Texas, Virginia, West Virginia 

AOSA examination list

Included

More information

For more information, see ISMA fact sheet.

Nomenclature

Family

Poaceae

Valid name

Poa annua L.

Synonyms

Poa annua L. var. aquatica Asch.
Poa annua L. var. reptans Hausskn.

 Poa annua . Woolly floret.
Poa annua. Woolly floret.
 Poa annua .  Floret with a strong and protruding rachilla.
Poa annua.  Floret with a strong and protruding rachilla.
From Left to Right: 1.  Poa annua  2.  Poa compressa  3.  Poa nemoralis  4.  Poa pratensis  5.  Poa trivialis . Florets with long hairs on the lemma curves, palea margins, and the callus.
From Left to Right: 1. Poa annua 2. Poa compressa 3. Poa nemoralis 4. Poa pratensis 5. Poa trivialis. Florets with long hairs on the lemma curves, palea margins, and the callus.