Family: Poaceae

Bouteloua aristidoides, commonly known as needle grama, is a North and South American native grass found in the southwestern United States and parts of Argentina. As a short, tufted annual, it is well-adapted to arid environments like deserts, dry plains, and washes. It was traditionally a natural component of these ecosystems, but it is now commercially sold for practical uses such as erosion control on dry, unstable soils and hillsides.

While not classified as a highly invasive threat in regions like Hawaii, needle grama possesses several traits that warrant caution. The species is highly tolerant of disturbance, thrives in roadsides and washes, and readily colonizes open sites. Its seeds are easily dispersed by wind, water, and attachment to animals or clothing, which could facilitate its spread into new areas. For the unique and fragile island ecosystems of Hawaii, which are highly vulnerable to invasion, introducing a plant with these weedy characteristics poses a potential risk. It could establish itself and compete with native plants in already disturbed or open habitats.

High Risk Traits:

• Broad climate suitability
  
• Allergenic to humans
  
• Wide soil tolerance
  
• Self-compatible (autogamous)
  
• Unintentional dispersal (roadsides, urban areas)
  
• Intentionally planted (erosion control)
  
• Wind-dispersed seeds
  
• Water-dispersed seeds (via flooding)
  
• Animal-dispersed seeds (external attachment)
  
• Persistent seed bank
  
• Benefits from fire and disturbance

Low Risk Traits:

• No spines, thorns, or burrs
  
• Not allelopathic or parasitic
  
• Non-toxic to animals
  
• Not shade tolerant
  
• Does not form dense thickets
  
• No vegetative reproduction
  
• Controlled by herbicides