Bromus arvensis

Species category

Agricultural, Weed

Common name

field brome, Japanese brome 

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

ObovateObovate:
Inverted egg shaped with apical end the broadest.

Size

  • Length: 6–8 mm
  • Width: 1–2 mm
  • Thickness: 1.5–2 mm

Color

Light brown to brown

Texture

Smooth

Lemma

Folded, widest two-thirds from the base; much wider than the caryopsisCaryopsis:
The single-seeded fruit or grain of the grass family (Poaceae); the fruit wall (pericarp) is united with the seed coat (testa).
and strongly involute.

Palea

Papery with long bristles or teeth on the margins; much shorter than the lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.
.

Other structures

AwnAwn:
A narrow, bristle-like organ, as on the glumes or lemmas of grasses (Poaceae).
and rachillaRachilla:
The axis of a spikelet.
with the same scar width; awnAwn:
A narrow, bristle-like organ, as on the glumes or lemmas of grasses (Poaceae).
near the tip of the lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.

Identification notes

The lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.
and caryopsisCaryopsis:
The single-seeded fruit or grain of the grass family (Poaceae); the fruit wall (pericarp) is united with the seed coat (testa).
are strongly laterally compressed, and the 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.
are nearly the same length.

Comments

Previously known as Bromus japonicus.

Noxious weed seed categories

AOSA examination list

Included

More information

For more information, see ISMA fact sheet.

Nomenclature

Family

Poaceae

Valid name

Bromus arvensis L.

Synonyms

Bromus anatolicus Boiss. & Heldr.
Bromus japonicus Thunb. 
Bromus japonicus Thunb. ssp. anatolicus (Boiss. & Heldr.) Penzes
Bromus japonicus Thunb. var. porrectus Hack.
Bromus patulus Mert. & W.D.J. Koch

 Bromus arvensis.  Brown, smooth florets.
Bromus arvensis. Brown, smooth florets.