Imperata cylindrica

Species category

Weed

Common name

cogongrass

Diagnostic characters

Planting unit

SpikeletSpikelet:
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.

Shape

Lanceolate

Size

  • Length 3–4 mm
  • Width 0.3–0.4 mm
  • Thickness 0.3–0.6 mm

Color

Light brown

Texture

Smooth

Lemma

Inside glumesGlume:
The pair of chaffy bracts that occur at the base of a grass spikelet, often completely enclosing it.
and sterile lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.
; thin and transparent.

Palea

Inside glumesGlume:
The pair of chaffy bracts that occur at the base of a grass spikelet, often completely enclosing it.
and sterile lemmaLemma:
One of two bracts of the grass floret; it is located on the side nearest the embryo and opposite the rachilla.
; thin and transparent.

Other structures

Many long, silky hairs from the callusCallus:
The hard base of grass florets or spikelets, just above the point of disarticulation.

Identification notes

SpikeletSpikelet:
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.
are very hairy. No awnsAwn:
A narrow, bristle-like organ, as on the glumes or lemmas of grasses (Poaceae).
. The 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.
are in pairs and attached to the rachisRachis:
The central axis of an inflorescence.
by unequal pedicels.

Noxious weed seed categories

State Noxious Weed: Georgia, Hawaii, Utah
Federal

Learn more on ITP's Federal Noxious Weed Disseminules tool.

AOSA examination list

Not included

Nomenclature

Family

Poaceae

Valid name

Imperata cylindrica (L.) P. Beauv.

Synonyms

Imperata arundinacea Cirillo
Lagurus cylindricus L.

 Imperata cylindrica . Florets with many long, silky hairs coming from the callus. 
Imperata cylindrica. Florets with many long, silky hairs coming from the callus. 
 Imperata cylindrica.  Florets with many long, silky hairs coming from the callus. Photo by Julia Scher, USDA-APHIS-PPQ.
Imperata cylindrica. Florets with many long, silky hairs coming from the callus. Photo by Julia Scher, USDA-APHIS-PPQ.
 Imperata cylindrica.  Caryopses. Photo by Julia Scher, USDA-APHIS-PPQ.
Imperata cylindrica. Caryopses. Photo by Julia Scher, USDA-APHIS-PPQ.
 Imperata cylindrica.  Hairy florets. Photo by Julia Scher, USDA-APHIS-PPQ.
Imperata cylindrica. Hairy florets. Photo by Julia Scher, USDA-APHIS-PPQ.