Bromus diandrus subsp. rigidus

Species category

Weed

Common name

ripgut 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

Lanceolate and long

Size

  • Length: 24 mm
  • Width: 1.5 mm
  • Thickness: 0.5 mm

Color

Brown; base dark brown becoming lighter toward the apexApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.

Texture

Short hispid hairs on the lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.
; hairs on the callusCallus:
The hard base of grass florets or spikelets, just above the point of disarticulation.
.

Lemma

ApexApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
bifid; nerves evident but not ridged.

Palea

Hairs on margins are short, coarse, and widely spaced.

Other structures

AwnAwn:
A narrow, bristle-like organ, as on the glumes or lemmas of grasses (Poaceae).
arises from the lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.
. The rachillaRachilla:
The axis of a spikelet.
is long. The callusCallus:
The hard base of grass florets or spikelets, just above the point of disarticulation.
has a rounded point.

Identification notes

AwnAwn:
A narrow, bristle-like organ, as on the glumes or lemmas of grasses (Poaceae).
is one to two times longer than the lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.
. CaryopsisCaryopsis:
The single-seeded fruit or grain of the grass family (Poaceae); the fruit wall (pericarp) is united with the seed coat (testa).
is long and thin.

Noxious weed seed categories

State Noxious Weed: Arizona, Wyoming

AOSA examination list

Included

More information

For more information, see ISMA fact sheet.

Nomenclature

Family

Poaceae

Valid name

Bromus diandrus Roth subsp. rigidus (Roth) Lainz

Synonyms

Anisantha rigida (Roth) Hyl.
Bromus diandrus Roth var. rigidus (Roth) Sales
Bromus maximus Desf., non Gilib.
Bromus rigidus Roth
Bromus villosus Forssk., non Scop.

 Bromus diandrus  ssp.  rigidus.  Florets with short, hispid hairs on the lemma.
Bromus diandrus ssp. rigidus. Florets with short, hispid hairs on the lemma.