Setaria viridis

Species category

Weed

Common name

green bristlegrass, bottle grass, pigeongrass, wild millet, green foxtail

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

OvalOval:
Broadly elliptic.

Size

  • Length 2–2.2 mm
  • Width 1–1.4 mm
  • Thickness 0.6–0.8 mm

Color

Yellow to dark brown, sometimes with dark speckles

Texture

Uniform minute ridges

Lemma

Hard, ovalOval:
Broadly elliptic.
, and arched

Palea

Hard, ovalOval:
Broadly elliptic.
, flat with shiny edges showing

Other structures

GlumesGlume:
The pair of chaffy bracts that occur at the base of a grass spikelet, often completely enclosing it.
present; the second glumeGlume:
The pair of chaffy bracts that occur at the base of a grass spikelet, often completely enclosing it.
is the same length as lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.
.

Identification notes

This species is found with both spikeletsSpikelet:
One or more florets that are subtended by a pair of bracts called glumes. Spikelets are pedicellate if located on a pedicle and sessile if attached directly to the rachis. Often spikelets with single florets have remnants of a second floret, usually a lemma.
and floretsFloret:
A small flower in a clustered inflorescence (e.g., sunflower, grasses). In grasses, a floret consists of the lemma, palea, stamens, and pistil.
. An occasional caryopsisCaryopsis:
The single-seeded fruit or grain of the grass family (Poaceae); the fruit wall (pericarp) is united with the seed coat (testa).
is identified by having minute flecks of blue or green in the pericarpPericarp:
Fruit wall; derived from the ovary wall.
. The full length of the second glumeGlume:
The pair of chaffy bracts that occur at the base of a grass spikelet, often completely enclosing it.
and the shiny edges of the paleaPalea:
One of the thin bracts of grass floret enclosing the fruit (caryopsis) that is located on the side opposite the embryo.
help identify these seeds.

Noxious weed seed categories

Not listed

AOSA examination list

Not included

More information

For more information, see ISMA fact sheet.

Nomenclature

Family

Poaceae

Valid name

Setaria viridis (L.) P. Beauv.

Synonyms

Setaria viridis (L.) P. Beauv. var. major (Gaudin) Pospichal
Panicum viride L. var. major Gaudin
Setaria viridis (L.) P. Beauv. var. robustaalba Schreib.
Setaria viridis (L.) P. Beauv. var. robustapurpurea Schreib.
Setaria viridis (L.) P. Beauv. var. viridis
Chaetochloa viridis
(L.) Scribn.
Panicum viride
 L.
Setaria viridis (L.) P. Beauv. var. breviseta (Döll) Hitchc.
Setaria viridis (L.) P. Beauv. var. weinmannii (Roem. & Schult.) Borbás

From Left to Right:  1.  Setaria pumila  ssp.  pumila  2.  Setaria faberi  3.  Setaria viridis  4.  Setaria italica. 
From Left to Right:  1. Setaria pumila ssp. pumila 2. Setaria faberi 3. Setaria viridis 4. Setaria italica. 
 Setaria viridis.  Florets with a full-length second glume and shiny palea edges.
Setaria viridis. Florets with a full-length second glume and shiny palea edges.