What is Cheatgrass?*

Illustration by Bellamy Parks Jansen.

Cheatgrass photo

Cheatgrass closeup photo

Cheatgrass photo

Cheatgrass in residential alley.

Cheatgrass photo

Map where cheatgrass can be found.

Cheatgrass drawing by Charlie Fifield of the Casper Field Office.

Common Name:
Life Span:

Bromos tectorum L.
Downy brome (cheatgrass, broncograss
Introduced (from Europe)
Inflorescence Characteristics:
  • type: panicle (5-15 cm long), dense, drooping, often purplish, branches and pedicels slender, flexuous
  • spikelets: 5- to 8-flowered (1.2-2 cm long, 3-6 mm wide excluding awns), glabrous to hirsute; margins thin, membranous; apical teeth slender (2-3 mm long)
  • awns: lemma awned (1.2-1.8 cm long), straight to bent
  • glumes: unequal, first glume (4-6 mm long), 1-nerved; second glume (8-10 mm long), 3-nerved, glabrous to hirsute; margins broad, hyaline
Vegetative Characteristics:
  • growth habit: cespitose or solitary
  • culms: erect or decumbent at base (25-60 cm tall), weak
  • sheaths: round, keeled toward collar, softly pubescent, margins connate
  • blades: flat (5-12 cm long, 3-7 mm wide), glabrous to hispid
  • ligules: membranous (2-3 mm long), acute, erose to lacerate
Growth Characteristics:

seeds germinate in the late fall or early spring, rapid spring growth, seeds mature about 2 months later, reproduces from seeds; an aggressive weed

Livestock Losses:

awns may injure eyes and mouths of grazing animals and contaminate fleece

Forage Value:

fair to good for livestock before the inflorescence emerges, then is practically worthless; deer and pronghorn graze it in the spring while it is actively growing; furnishes food for some upland birds and rodents


heavily grazed rangeland, roadsides, waste places, and disturbed sites; adapted to a broad range of soil textures, most abundant on dry sites

* Reproduced from NORTH AMERICAN RANGE PLANTS by James Stubbendieck, Stephan L. Hatch, and Charles H. Butterfield, illustrated by Bellamy Parks Jansen, by permission of the University of Nebraska Press. c 1981, 1982, 1986, 1992, 1997 by the University of Nebraska Press.