SafePlants

Spike Bentgrass (Agrostis exarata)

Spike bentgrass, also known as spike bent, Pacific bentgrass, and spike redtop, is a perennial bunchgrass found across a wide range of habitats in western North America.

Considerations for Pets

• This plant is a grass.
• Grows along the edges of streams.
• Has small parts.

Taxonomy and Nomenclature

• Scientific Name: Agrostis exarata Trin.
• Common Names: Spike bentgrass, spike bent, Pacific bentgrass, spike redtop, western bentgrass
• Family: Poaceae (Grass Family)
• Synonyms: Agrostis aenea, Agrostis alaskana, Agrostis ampla, Agrostis asperifolia, Agrostis exarata (Note: some of these are listed as synonyms for Agrostis exarata but also appear as the primary scientific name.)

Distribution and Habitat

• Native to western North America.
• Occupies a wide range of habitats and altitudes.
• Found from Manitoba, South Dakota, Nebraska, Texas, and Mexico west to the Pacific coast.
• Mentioned as known in New England (though likely not native).
• Grows at low to mid elevations in moist sites.
• Naturally grows along the edges of streams.

Morphological Characteristics

• Perennial bunchgrass with short rhizomes.
• Cool season species.
• Grows to 4 feet (approximately 120 cm) but usually no more than 2 feet (approximately 60 cm) tall.
• Stems (culms) are slender, ranging from 20-100 cm in height.
• Leaves have blades mostly 2-8 mm broad, and ligules 0.5-2 mm long.
• Inflorescence is a contracted panicle.
• Dense, spike-like flower head (panicle).
• At maturity, the flowerhead is a spike, and spikelets diverge from the stem.

Ecological Role

• Used for disturbed sites, culvert removal, side cast, pull back, reclamation, and various projects.
• Used in efforts to exclude Scotch broom.