Family: Fabaceae
Aeschynomene americana, commonly known as American joint vetch, is a fast-growing legume native to tropical regions of the Americas. It is widely used as a forage crop because of its nitrogen-fixing ability, high palatability to livestock, and rapid establishment in pastures. This annual or short-lived perennial herb thrives in moist soils, producing numerous branches with small, delicate leaflets that close when touched. It also improves soil fertility by fixing atmospheric nitrogen, making it useful in agricultural systems as a cover crop or green manure.
Although widely cultivated in other tropical regions, American joint vetch is not currently naturalized in the Hawaiian Islands. However, its rapid growth and prolific seed production raise concerns that it may become a weed of other crops if not carefully managed. In some regions, it has spread beyond intended areas of cultivation, interfering with agricultural production. For Hawaiʻi, this means the species should be used with caution and monitored closely to prevent potential impacts on local farming systems.
High Risk Traits:
- Naturalized in multiple regions (e.g., India, Sri Lanka, Florida)
- Agricultural weed (e.g., in rice fields)
- Repeatedly introduced outside native range
- Tolerates a range of soil types
- Nitrogen-fixing ability
- Self-pollinating
- Short generation time (annual or short-lived perennial)
- Intentionally spread as forage
- Animal-dispersed (via cattle)
- Persistent seed bank
- Tolerates grazing and regrows well
Low Risk Traits:
- Shade-intolerant
- No spines or thorns
- Not allelopathic
- Not parasitic
- Palatable to livestock
- Non-toxic
- Not a major pest or disease host
- Not dispersed by wind, water, or birds
- Not a prolific seed producer
