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Weed Identification

smooth brome

Family

Poaceae

Scientific Name

Bromus inermis

Other Common Names:

hungarian bromegrass
awnless brome
Russian brome
hungarian brome
austrian brome
bromegrass

Habit

Smooth brome is an upright grass that can grow to 4 feet tall.

Leaves

The plant produces numerous basal and stem leaves that vary in length from 4 to 10 inches. Frequently the leaves are marked by a transverse wrinkle resembling a "W" a short distance below the tip. Leaf blades tend to be glabrous but can have some hairs.

Identifying Characteristics

Bromus inermis, smooth brome, is a leafy, sod-forming, perennial, cool season grass that spreads by rhizomes. This species is both native and introduced. The stems vary in height from 2 to 4 feet. There are approximately 136,000 seeds per pound. Smooth brome is the most widely used of the cultivated bromegrasses and has been cultivated in the U.S. since the early 1880s.

Flower Seed Head

The flower head develops a characteristic rich purplish-brown color when mature.

Seed Fruit

The seed is produced in semi-compact 5 inch long panicles with ascending branches. The flat compressed seed is usually awnless, about 1/3 inch long, and smooth.

Where Found

Smooth brome is best adapted to cooler climates and is generally hardier than tall fescue or orchardgrass. It is resistant to drought and extremes in temperature. This plant is very susceptible to disease in areas of high humidity. Smooth brome grows best on slightly acid to slightly alkaline well drained clay loam soils with high fertility but it will also grow well on lighter textured soils where adequate moisture and fertility are maintained. Smooth brome performs best in a pH range of 6.0 to 7.5. Stands are difficult to obtain and growth is poor on soils high in soluble salts. Smooth brome is distributed throughout most of the United States.

Leaf Hair on Upper Surface

Varies: 
no hairs
hairs from base to tip

Leaf Arrangement

rolled in bud

Mature Leaf Width

Varies: 
less than 5 mm
6 to 15 mm
more than 15 mm

Stem

flat or oval

Seedhead

panicle

Root Structure

fibrous

Life Cycle

winter annual

Auricle

not present

Ligule

membrane

Ligule Length

Varies: 
less than 1 mm
1-2 mm

Plant Type

Grass