SafePlants

Tall Oat-grass (Arrhenatherum elatius)

Arrhenatherum elatius, commonly known as false oat-grass, tall oat-grass, tall meadow oat, onion couch, or tuber oat-grass, is a perennial grass species found in various habitats.

Taxonomy and Nomenclature

• Scientific Name: Arrhenatherum elatius (L.) Presl, or Arrhenatherum elatius (L.) Beauv. ex J.& K. Presl
• Family: Grass Family
• Genus: Arrhenatherum (containing approximately six species)
• Synonyms/Alternative Names: Oat Grass, False Oat Grass, Meadow Oat Grass, Tall Meadow Oat Grass

Distribution and Habitat

• Native to temperate Europe and Asia.
• Introduced to other regions, including the United States.
• Found in grasslands, roadside verges, and disturbed grounds.
• Observed in locations such as Ojdula, Transylvania, Romania, and the central Columbia River Gorge (Memaloose area).

Ecological Role

• Considered a non-native and invasive species in some parts of the United States.
• There are two subspecies.

Morphological Characteristics

• Perennial, clump-forming grass.
• Tussock-forming, growing in tufts.
• Erect, smooth stems ranging from 28-70 inches tall.
• Stems are sometimes hairy at the nodes and often swollen and bulb-like at the base.
• Leaf blades are flat.
• Produces shoots very early in the spring with strongly upright growth.

Growth Habits

• Goes dormant during the summer and carries out its life cycle during the winter months.
• Moderate regrowth after cutting.

Interactions with Other Organisms

• Can be affected by Tall oatgrass mosaic virus (TOgMV), a member of the genus Tritimovirus.
• Observed to interact with Red-and-White Spiders (Enoplognatha).
• Can affect seed yield in dry peas (Pisum sativum L.) as a volunteer plant.

Additional Information

• USDA PLANTS Symbol: AREL3
• Can be controlled with diquat desiccant applied at the beginning of the seed dough maturity stage for seed production.