Family: Cactaceae
Acanthocereus tetragonus, commonly called barbed-wire cactus or sword-pear, is a sprawling, climbing cactus with long, spiny stems. Native to the Americas, it has spread to tropical regions worldwide and is now naturalized in parts of Hawaiʻi. This species can grow rapidly, forming dense thickets that smother other plants and restrict access for people and animals. It reproduces easily from both seeds and stem fragments, making it very difficult to remove once established.
Because of its aggressive growth and ability to invade natural and agricultural areas, A. tetragonus is considered a high-risk plant for Hawaiʻi and the Pacific. While its fruits and stems are edible once the spines are removed, its negative impacts outweigh its limited uses. Management often requires persistent effort and herbicide treatment, and prevention is the most effective way to avoid new infestations.
High Risk Traits:
- High Risk / Undesirable Traits
- Grows in tropical climates
- Naturalized on Kauai (Hawaiian Islands), Queensland, Australia and New Caledonia
- A weed of deer breeding farms in New Caledonia
- An environmental weed in Australia
- Spiny
- Tolerates some shade
- Clambering over other vegetation
- Forms dense thickets
- Reproduces by seeds and vegetatively (rooting at branch tips)
- Seeds dispersed by birds, other animals and intentionally by people
- Resprouts after cutting (unless treated with herbicide)
Low Risk Traits:
- Non-toxic (edible fruit and stems if spines are removed)
- Herbicides may provide effective control
