Family: Lamiaceae

An invasive shrub that spreads aggressively from root suckers. Native to subtropical China, C. chinense is the most common garden escapee in the genus. A pan-tropical weed, C. chinense, is invasive in Central America, South America, Puerto Rico, and other Pacific Islands. Naturalized on all the main Hawaiian Islands, it was already considered a weed in Hawaiʻi by 1917. This plant thrives in areas of deep shared and poor soil. A plantation pest, farmers of coconut, cacao and banana have reported this plant as weedy. In Hawaiʻi, it invades roadsides, disturbed areas, taro paddies, and stream beds. The Division of Forestry and Wildlife of the Hawaiʻi Department of Land and Natural Resources has designated this species as one of “Hawaiʻi’s Most Invasive Horticultural Plants.”

Description and Dispersal:

• Scented shrub up to 8 ft tall
  
• Heart-shaped leaves (2-12 in long by 2-11 in wide) grow opposite
  
• Clusters of fragrant red and pink flowers (1 in)
  
• Primarily spread by root suckers and vegetative fragmentation

High Risk Traits:

• High climate suitability for tropics/subtropics
  
• Widely introduced and naturalized globally
  
• Forms dense, shading thickets
  
• Weed in gardens, agriculture, and natural areas
  
• Tolerates shade and poor soils
  
• Spreads aggressively via root suckers and fragments
  
• Resistant to grazing; unpalatable to livestock
  
• No effective local natural enemies
  
• Tolerates slashing and regrows readily
  
• Can expand rapidly in open areas (6–8 m/year)

Low Risk Traits:

• No spines, thorns, or burrs
  
• Not parasitic or toxic to humans
  
• Does not increase fire risk
  
• Sterile form common (no seeds/fruit)
  
• No persistent seed bank
  
• Controllable with herbicides
  
• Not wind, bird, or externally animal-dispersed