SafePlants

Aristida purpurea (Purple Threeawn)

Aristida purpurea, commonly known as Purple Threeawn, is a species of grass native to North America.

Considerations for Pets

• This grass is sometimes referred to as "Wire Grass."

Scientific Classification and Nomenclature

• Scientific Name: Aristida purpurea Nutt.
• Synonym: Aristida glauca
• Family: Poaceae (Grass Family), specifically the Aristidoideae subfamily and Aristideae tribe.
• Common Names: Blue Threeawn, Reverchon Threeawn, Tres Barbas Purpura, Purple 3-awn, Wire Grass, Purple three awn, Purple threeawn, Red threeawn.
• Varieties:
  • Aristida purpurea var. nealleyi (blue threeawn, Nealley's threeawn)
  • Aristida purpurea var. parishii (Parish's threeawn)
• Note: The text lists Aristida glauca as a synonym for Aristida purpurea, but elsewhere it's referred to as blue threeawn, and also listed separately.

Distribution and Habitat

• Native to North America.
• Blue Threeawn (A. p. var. nealleyi) is found from southern California east to southern Utah and Oklahoma, and south to northern Mexico.
• Parish's Threeawn (A. p. var. parishii) is found in southern California and southern regions.
• Found growing in dry gravelly areas.

Morphological Characteristics

• Grows to be between 14 and 31 inches in height.
• Foliage can range in color from green to blue.
• Perennial grass.
• Prefers dry conditions and full sun.
• Stems and leaves are sometimes blue-green.

Ecological Role

• Forage value depends on the other species growing nearby.

Interactions with Other Organisms

• Commonly found growing alongside big sagebrush, cheatgrass, needle-and-thread, western wheatgrass, blue grama, and annual forbs.
• Research has been conducted on its interaction with blue grama (Bouteloua gracilis) and western wheatgrass to predict biomass and measure plant response to fire.

Additional Information

• This plant is used in streetscapes and in tight spaces such as parkways and medians.
• Watering guidance suggests to "water abundantly, moistening the soil deeply with 1-2 buckets of water, but let's act only when the substratum is dry".

Further Information

• Dave's Garden is mentioned as a community where people share tips and ideas for gardens, along with seeds and plants.
• Intermountain Herbarium is credited for information and likely imagery of Red Threeawn.
• Hitchcock, A.S. (rev. A. Chase). 1950. Manual of the grasses of the United States. Washington, DC.