Family: Cannabaceae

Cannabis sativa—commonly known as marijuana, hemp, or paka lolo—is a fast-growing annual plant native to Central and South Asia that has been cultivated by people for thousands of years. It has an upright, branching form with distinctive palm-shaped leaves and produces small, inconspicuous flowers. Different varieties have been selected for different purposes: hemp types are grown for strong natural fibers, seeds, and oils used in textiles, food products, and industrial materials, while other varieties have been cultivated for medicinal, ceremonial, or recreational uses. In Hawaiʻi, Cannabis sativa has historical and cultural significance, as well as modern economic interest tied to regulated medical and industrial hemp uses.

From an environmental standpoint, Cannabis sativa is not considered a major invasive plant in Hawaiʻi and generally does not persist or spread aggressively without human care. However, unmanaged plants can form feral populations in disturbed areas, and pollen from male plants can travel long distances, complicating nearby cultivation efforts. The primary concerns associated with this species are social, legal, and regulatory rather than ecological, as cultivation and possession are strictly regulated under state and federal law. Any planting or management of Cannabis sativa should follow current regulations to avoid legal risks and unintended impacts.

High Risk Traits:

• Broad climate suitability and elevation range, demonstrating environmental versatility
  
• Grows in temperate to subtropical climates
  
• Widely naturalized (cultivated on main Hawaiian Islands)
  
• A disturbance-adapted plant; weedy types may adversely impact agriculture
  
• May be toxic to certain animals
  
• May cause adverse effects to humans; pollen may be allergenic
  
• Sun-loving, but can tolerate shade
  
• Tolerates many soil types
  
• Weedy types may form dense stands
  
• Reproduces by seeds
  
• Domesticated and wild types can freely hybridize
  
• Mostly self-incompatible (or dioecious), but low levels of selfing may occur in some wild types
  
• Able to reach maturity in under one year
  
• Seeds dispersed by humans, animals, water, possibly wind and birds
  
• Viable seeds can survive gut passage
  
• Some viable seeds may persist in the soil for three to four years

Low Risk Traits:

• Long history of domestication; domesticated types cultivated for medicinal uses less likely to escape
  
• Unarmed (no spines, thorns, or burrs)
  
• Provides fodder for livestock (palatable despite some toxic properties)
  
• Not reported to spread vegetatively
  
• Mostly self-incompatible (or dioecious), but low levels of selfing may occur in some wild types
  
• Herbicides and mechanical methods may provide effective control if removal is desired