SafePlants

Smooth Brome (Bromus inermis)

Smooth brome, scientifically known as Bromus inermis, is a widely recognized grass species with several common names, including bromegrass, brome grass, cheat grass, and chess grass.

Taxonomy and Nomenclature

• Scientific Name: Bromus inermis Leyss.
• Family: Poaceae (Grass family, formerly Gramineae)
• Synonyms: Smooth bromegrass, brome inerme
• Subspecies:
  • Bromus inermis subsp. inermis (Awnless brome, Hungarian brome)
  • Bromus ramosus ssp. ramosus (lesser hairy brome)

Distribution and Habitat

• Native to Europe and Asia.
• Introduced to the United States from Hungary in 1884. Also introduced to California from Europe in the early 1880s.
• Widely distributed throughout most of the contiguous United States, except for a few southeastern states. Very common in the northern states.
• Common pasture and hay grass in the northern United States and Canada.

Ecological Role

• Considered a non-native invasive species in some regions.
• Invasion is most common in mixed grass prairie regions and disturbed portions of old pastures in the tallgrass and mixed prairie.
• Introduced strains can eliminate native grasses and forbs.
• Smooth brome invasion can lead to increased soil nitrogen, soil carbon, and root biomass.

Morphological Characteristics and Growth Habits

• A long-lived perennial, sod-forming grass.
• Cool-season grass that grows best during cool weather months.
• Height: Typically grows to 2-3 feet (0.6-0.9 meters) tall, sometimes reaching 1-3.5 ft (0.3-1.1m) tall or up to 20-150 cm tall.
• Usually unbranched, with light green, hairless or short-pubescent, terete culms (stems).
• Leaves have a fine texture and are alternate, measuring 0.25-0.75 inches wide, typically hairless with broad leaves.
• Rhizomatous grass with deep, fibrous, and very fine roots.
• Matures somewhat later in the spring than orchardgrass and makes less summer growth.

Uses

• Widely planted as a forage grass and for hay production.
• Used for erosion control.
• Suitable for horse hay.

Interactions with Other Organisms

• Armyworms have been reported in smooth brome pastures and hay fields.
• Subject to pathogenic fungal species, which can be isolated from leaves and seeds.

Additional Information

• Average seed yield is 100-125 kg/ac.

Resources and Further Information

• USDA NRCS Plant Materials Program
• AGRICULTURAL EXPERIMENT STATION AND COOPERATIVE EXTENSION SERVICE, KANSAS STATE
• College of Agriculture & Biological Sciences/USDA
• College of Agriculture and Life Sciences