SafePlants

Mountain Brome: A Versatile Native Grass

Mountain brome (Bromus marginatus) is a valuable native grass found in mountainous areas of western North America. It is also known by the common names mountain bromegrass, large mountain brome, and California brome. Other common names include bromes, brome grasses, cheat grasses, and chess.

Taxonomy and Nomenclature

• Scientific Name: Bromus marginatus Nees ex. Steudel
• Family: Poaceae (Grass family)
• Plant Symbol: BRMA4 (USDA PLANTS database)
• Synonyms: Bromus carinatus var. marginatus
• Taxonomic Rank: Subspecies (mentioned in context of a synonym)

Distribution and Habitat

• Native to western North America, including the Intermountain West, Northern and Central Rocky Mountains, and Pacific Coast regions.
• Found in nearly all of the mountainous areas of Utah.
• Introduced in New York and New England, where it inhabits fields and roadsides.
• The UP Cold Springs Germplasm Mountain brome originated on the Uncompahgre Plateau in western Colorado.

Morphological Characteristics and Growth Habits

• A robust, erect bunchgrass, growing between 60 and 120 cm (approximately 2 to 4 feet) high.
• Short-lived perennial.
• Reproduces through seeds.
• Grows from 1-4 ft. in height.
• Leaves can grow up to 12 inches long.
• Does not have rhizomes.

Ecological Role

• Adapted to a wide spectrum of relatively moist soils, including thin, infertile sites.
• Intolerant of high water tables.
• Used widely for grazing.
• Useful for dryland pasture, erosion control, and soil stabilization.
• Establishes rapidly and can provide quick cover.

Interactions with Other Organisms

• The flowers are hermaphrodite (have both male and female organs) and are pollinated by wind.
• Can be affected by head smut (Ustilago bullata).

Further Information

• USDA NRCS Idaho State Office
• USDA PLANTS Database
• Encyclopedia of Life
• ResearchGate
• Intermountain Herbarium