Family: Plantaginaceae

Collinsia heterophylla (Chinese houses) is a native wildflower from California, known for its charming tiered blossoms that resemble a pagoda or “Chinese house.” This annual plant grows up to 1–2 feet tall, with delicate, square-stacked flowers that range from pale lavender to deep purple, often fading to white at the edges. Chinese houses thrives in well-drained soils and full sun, making it a favorite in gardens for adding seasonal color and attracting pollinators like bees and butterflies. Its modest size and cascading blooms make it ideal for borders, rock gardens, and naturalized wildflower areas.

Although Collinsia heterophylla is currently not known to be naturalized in Hawaii, it does possess traits that are cause for concern and could detrimentally impact tropical island ecosystems if it spreads. Its rapid self-seeding and adaptability mean it could compete with native plants in vulnerable habitats. Gardeners are encouraged to choose a low-risk or native alternative to help protect Hawaii’s unique and delicate ecosystems.

High Risk Traits:

• Elevation range exceeds 1000 m, and can grow in >5 hardiness zones demonstrating environmental versatility
  
• Possibly Naturalized outside native range
  
• Shade-tolerant
  
• Tolerates many soil types
  
• Forms dense stands in native range
  
• Self-compatible
  
• Able to hybridize with other Collinsia species
  
• Able to reach maturity in <1 year (annual herb)
  
• Seeds dispersed passively by dehiscence and intentionally by people
  
• Small seeds could possibly be accidentally dispersed
  
• Capable of prolific seed production
  
• Seeds able to be stored for extended periods and show dormancy. May form a persistent seed bank
  
• Limited ecological information, particularly on dispersal vectors, makes accurate risk prediction difficult

Low Risk Traits:

• Despite possible naturalization, no reports of negative impacts documented
  
• Mediterranean to temperate climate species (may only become established at higher elevations in the tropics)
  
• Unarmed (no spines, thorns or burrs)
  
• No reports of toxicity
  
• Ornamental
  
• Beneficial to bees and other pollinators
  
• Not reported to spread vegetatively