False Brome
Brachypodium sylvaticum
Washington State Classification
Class A — Eradication Required Statewide
It is a fast-spreading, invasive grass that displaces native flora.
Quick Reference
Identification
Growth Habit
It is a perennial, loosely tufted grass with upright stems. Hairs on leaves, leaf sheaths and nodes are noticeable but variable. Plants often have a distinctive lime-green coloration that persists much of the year.
Leaves
Leaf sheaths are not fused and are typically covered with spreading hairs (though sometimes hairless). Leaf blades are flat and reflexed, appearing arched or nodding and are up to 14 inches long. They are sparsely covered by long, soft hairs.
Flowers
Flowers grouped in somewhat upright to nodding, narrow spikes (racemes). Variable hairiness is present through the flowers. They typically have little to no stalk connecting them to the main stem. Flowers bloom and form seed generally June to September.
Fruit & Seeds
Seed structures (called a caryopsis, a typical achene-like fruit of grasses) are hairy at the tip.
Impact
It is a fast-spreading, invasive grass that displaces native flora. It can form dense, monotypic colonies in both forest understories and open woodlands. It is rapidly expanding in Oregon and is capable of expanding quickly into Washington.
Ecology & Spread
Habitat
It can grow in a variety of habitats including forests, forest edges, woodlands, riparian areas, prairies and roadsides. Please click here to see a county level distribution map of false brome in Washington.
Spread Mechanisms
Reproduction
False brome reproduces by seed.
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Control Methods
Mechanical
- Mowing for multiple years to exhaust the seed bank and mowing as a pre-treatment to herbicide application can be effective at helping to control false brome. Small patches can be hand pulled in the spring.