Family: Euphorbiaceae
Origin, Description & Uses
Euphorbia grandicornis, commonly known as cow’s horn or big horned euphorbia, is a succulent plant native to southern Africa. This striking plant grows as a large, upright shrub or small tree with thick, segmented stems that feature prominent spiny ridges resembling cow horns. Its unique appearance makes it a popular ornamental for xeriscaping, rock gardens, and container planting. Like many euphorbias, it produces a milky sap that has been used locally for traditional medicinal purposes, though it is toxic if ingested or if it comes into contact with skin and eyes.
Risks & Threats
Although Euphorbia grandicornis is not currently naturalized in Hawaii, it possesses traits that warrant caution. Its rapid growth, ability to propagate vegetatively, and toxic sap are characteristics that could allow it to become invasive under the right conditions. Because its ecological impact in tropical island ecosystems is not yet fully understood, further evaluation is needed to determine whether it could spread and outcompete native plants.
High Risk Traits:
- Grows in tropical climates
- Related Euphorbia species have become invasive
- Sap toxic and an irritant to people and possibly also animals
- Tolerates many soil types
- Seeds dispersed by dehiscent capsules and people
- Limited ecological information from native and introduced ranges makes accurate risk predications difficult
Low Risk Traits:
- No reports of naturalization or invasiveness world wide (but outdoor cultivation in tropical climates may be limited)
