Family: Apocynaceae
Asclepias curassavica, known as blood flower, butterfly weed, or red milkweed, is a striking perennial native to the American tropics. It’s valued for its clusters of bright orange and red flowers that attract butterflies, bees, and other pollinators. The plant is especially popular among gardeners for supporting monarch butterflies, as its leaves serve as a food source for monarch caterpillars. It grows easily in full sun and well-drained soils and is often used in pollinator gardens and educational settings.
However, in Hawaiʻi, Asclepias curassavica is naturalized and can spread beyond cultivation, particularly in disturbed or open areas. While it supports butterfly populations, it may also disrupt native ecosystems or compete with local vegetation. Because of its invasive potential and ecological impacts, planting native or non-invasive alternatives or other locally appropriate species is recommended.
High Risk Traits:
- Elevation range exceeds 1000 m, demonstrating environmental versatility
- Thrives in tropical climates
- Naturalized (including main Hawaiian Islands)
- Latex highly caustic to the skin, possibly poisonous if ingested
- Tolerates many soil types
- Seeds dispersed by birds and intentionally by people
- Seeds able to be stored for extended periods; May form a persistent seed bank
- Able to coppice and resprout after cutting
Low Risk Traits:
- No reports of invasiveness or naturalization (with the possible exception of Oahu(), but no evidence of widespread introduction outside native range
- Unarmed (no spines, thorns or burrs)
- Provides fodder for livestock (palatable despite reports of toxicity)
- Ornamental
- Not reported to spread vegetatively
- Limited ecological information makes accurate risk prediction difficult
