Family: Poaceae

Origin, Description & Uses
Muhlenbergia capillaris (hairawn muhly, pink muhly) is a perennial ornamental grass native to the central and eastern United States, extending south through Guatemala and parts of the Caribbean. It is best known for its airy, cloud-like plumes of pink to purplish flowers that appear in late summer to fall, creating a striking visual display in landscapes. The plant forms dense clumps of fine, arching green foliage and is widely used in ornamental horticulture for borders, mass plantings, and naturalistic garden designs. It is also valued for its drought tolerance and low maintenance needs, making it popular in sustainable landscaping and erosion control in suitable climates.

Risks & Threats
Although Muhlenbergia capillaris is not known to be naturalized in the Hawaiian Islands, it does possess traits that are cause for concern. As a prolific seeding ornamental grass adapted to a range of environments, it has the potential to escape cultivation and establish in disturbed or open habitats under favorable conditions. Like other ornamental grasses, it could contribute to altered fire behavior in dry landscapes and compete with native vegetation if it were to spread. Ongoing evaluation is needed to determine if it could impact Hawaii, and caution is recommended to ensure it will not negatively affect local ecosystems.

High Risk Traits:

• Broad climate suitability and wide natural range
  
• Adaptable to tropical climates
  
• Related species have become invasive
  
• Tolerates many soil conditions (and potentially able to exploit many different habitat types)
  
• Tolerates fire and could increase fire risks
  
• Can form almost pure ground cover in native range (could exclude other species)
  
• Reproduces by seeds which may be dispersed externally on the fur of animals

Low Risk Traits:

• No records of naturalization or invasiveness reported
  
• Non-toxic
  
• Landscaping and ornamental value
  
• Genus Muhlenbergia susceptible to herbicides