Family: Poaceae

Origin, Description & Uses
Oloptum miliaceum (rice millet, smilo) is a perennial grass native to Macaronesia and a broad region extending from the Mediterranean basin through to Iran. It forms clumping to loosely spreading tufts of slender, upright stems with narrow leaves and open, airy seed heads that can give it a light, fountain-like appearance. In some regions it has been used as a forage grass for grazing livestock and is occasionally planted for erosion control or as a low-maintenance ornamental in dry or semi-dry landscapes.

Risks & Threats
This species is naturalized on Maui and Hawaiʻi Island and is considered high risk due to its ability to spread beyond planted areas. It produces abundant seeds that are readily dispersed, allowing it to establish in disturbed sites, grasslands, and open habitats where it can compete with native vegetation. Like many introduced grasses, it can contribute to habitat degradation and may increase fire risk by adding fine, dry fuels to the landscape. Because it possesses traits that are cause for concern and could detrimentally impact tropical island ecosystems, it is recommended to choose low-risk or native alternatives when suitable options are available.

High Risk Traits:

• Native to subtropical regions
  
• Naturalized in Hawaii and California
  
• Weed of disturbed, riparian, and urban areas
  
• Environmental weed in Australia
  
• Shade tolerant
  
• Wind-pollinated
  
• Seed contaminant
  
• Dispersed unintentionally (traffic), intentionally (erosion control), by wind, water, and animals
  
• Regenerates after fire

Low Risk Traits:

• Palatable to grazing animals
  
• Non-toxic to humans or animals
  
• No spines, thickets, or vegetative reproduction
  
• Ornamental value
  
• Possibly controllable with herbicides