Family: Cannabaceae
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
