Family: Poaceae

Origin, Description & Uses
Urochloa mutica (formerly known as para grass) is a perennial tropical grass native to northern and sub-Saharan Africa, extending east to the Middle East and the southwestern Arabian Peninsula. It has long, creeping stems that root readily at the nodes, allowing it to form dense, lush stands in wet environments. Because of its rapid growth, high biomass production, and tolerance of flooding, it has been widely introduced throughout the tropics as a forage grass for cattle and for erosion control in moist areas. In Hawaiʻi, it is naturalized on Kuaihelani (Midway Atoll), Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, Maui, and Hawaiʻi Island, where it commonly occurs from sea level to about 1,060 m (3,480 ft).

Risks & Threats
Urochloa mutica is naturalized in Hawaiʻi and possesses traits that are cause for concern because it can detrimentally impact tropical island ecosystems. It spreads aggressively by creeping stems that readily root and expand into dense mats, particularly in wetlands, along streams, drainage ditches, roadsides, and other disturbed, high-moisture habitats. These thick infestations can outcompete native wetland and riparian vegetation, alter water flow, reduce habitat quality, and make restoration efforts more difficult. Because this species is already widespread across the Hawaiian Islands, landowners and land managers should avoid planting it in new locations and prioritize preventing its spread into areas where it is not yet well established, especially sensitive natural areas and wetlands. Whenever possible, choose a low-risk or native alternative for forage, groundcover, or erosion control to help protect Hawaiʻi’s unique ecosystems.

High Risk Traits:

• Broad climate suitability, and elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Thrives in tropical climates
  
• Naturalized on Midway Atoll, Kauai, Oahu, Lanai, Molokai, Maui, and Hawaii (Hawaiian Islands) and widely naturalized elsewhere (native range unknown)
  
• An agricultural and significant environmental weed
  
• Other Urochloa (formerly Brachiaria) species are invasive
  
• Allelopathic
  
• May be toxic to horses in certain situations
  
• Host of crop pests and pathogens
  
• Increases fuel load and fire risk
  
• Moderately shade tolerant
  
• Tolerates many soil types
  
• Forms dense cover that excludes other vegetation
  
• Reproduces by seed (rarely) and vegetatively by trailing stems and fragments
  
• Apomictic
  
• Vegetative fragments and seeds (when produced) dispersed by water
  
• Intentionally cultivated by humans as cattle forage
  
• May tolerate some fire and moderate grazing

Low Risk Traits:

• Regarded as a weed of sugar cane, which is no longer an important economic crop in Hawaii. Grass may now be more value for its palatability to cattle
  
• Unarmed (no spines, thorns, or burrs)
  
• Highly palatable to grazing animals
  
• Reduced, or lack of, seed production minimizes risk for long distance dispersal
  
• Herbicides may provide effective control