Family: Acanthaceae

Origin, Description & Uses
Ruellia tuberosa (minnieroot) is a flowering herbaceous plant native to Mexico, northern South America, Peru, and the Caribbean. It typically grows in open, sunny areas and is recognized by its upright stems, opposite leaves, and striking purple, trumpet-shaped flowers. The plant produces small, capsule-like fruits that can explosively release seeds when mature. Minnieroot has been used in traditional medicine in parts of its native range, and it is also occasionally grown as an ornamental for its attractive blooms and ability to tolerate dry conditions.

Risks & Threats
Although Ruellia tuberosa is currently not known to be naturalized in the Hawaiian Islands, it possesses traits that are cause for concern, including rapid growth, prolific seed production, and an effective ballistic seed dispersal mechanism that can spread plants over a wide area. In tropical environments, these characteristics may allow it to establish quickly and potentially compete with native vegetation, particularly in disturbed habitats. If introduced and established, it could contribute to changes in plant community structure and reduce habitat quality for native species. Because of these potential risks, it is recommended to choose a low-risk or native alternative when suitable options are available for landscaping or restoration projects.

High Risk Traits:

• Naturalized beyond native range (Asia, Pacific, Caribbean)
  
• Invasive weed in India
  
• Congeneric (R. tweediana) is a Category I invasive in Florida
  
• High tropical climate suitability
  
• History of repeated introductions
  
• Reproduces by seeds and tubers (geophyte)
  
• Self-compatible (cleistogamous flowers)
  
• Prolific seed production (explosive capsules)
  
• Dispersed unintentionally (roadsides, waste places)
  
• Dispersed intentionally (commercially sold)
  
• Dispersed by water and externally by animals

Low Risk Traits:

• Narrow climate range (USDA zones 9–11)
  
• No confirmed agricultural or environmental weed impacts
  
• No spines, thorns, or burrs
  
• Not toxic to humans
  
• No wind, bird, or gut dispersal
  
• No persistent seed bank (>1 year)