Family: Euphorbiaceae

Origin, Description & Uses
Euphorbia cyathophora, commonly known as dwarf poinsettia, fire-on-the-mountain, Mexican fire plant, or painted spurge, is a small annual herb native to tropical and subtropical regions of the Americas. It is recognized for its striking foliage, with green leaves often marked by bright red, orange, or cream-colored patches near the tips, giving it a showy, poinsettia-like appearance. This fast-growing plant thrives in sunny, disturbed areas such as roadsides, fields, and gardens. It has been used as an ornamental for its colorful display and is sometimes found in informal plantings or naturalized landscapes.

Risks & Threats
In Hawai‘i, Euphorbia cyathophora is naturalized across multiple islands, including Kuaihelani (Midway Atoll), Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi. It possesses traits that are cause for concern, such as rapid growth, prolific seed production, and the ability to establish in disturbed habitats, allowing it to spread beyond cultivation. These characteristics may enable it to compete with native vegetation and alter plant communities in sensitive environments. Because of its potential to detrimentally impact tropical island ecosystems, this species is considered high risk. Gardeners and land managers are encouraged to avoid planting it and instead choose low risk or native alternatives better suited to Hawai‘i’s unique ecosystems.

High Risk Traits:

• Broad latitudinal range
  
• Thrives in tropical climates
  
• Naturalized on Midway Atoll, Kauai, Oahu, Molokai, Maui and Hawaii (Hawaiian Islands), and widely naturalized elsewhere
  
• A weed of disturbed sites and an environmental weed in Australia and Midway Atoll
  
• Other Euphorbia species are invasive
  
• Toxic to animals and people
  
• Tolerates many soil types
  
• Able to form dense thickets
  
• Reproduces by seeds
  
• An annual, reaching maturity in one growing season
  
• Mature capsules open explosively, expelling seeds short distances.
  
• Seeds also dispersed by water, in dumped garden waste, and intentionally cultivated by people as an ornamental
  
• Prolific seed production

Low Risk Traits:

• Unarmed (no spines, thorns, or burrs)
  
• Palatable to grazing animals (despite toxicity)
  
• Valued as an ornamental
  
• Grows in full sun (shade may inhibit spread)
  
• Not reported to spread vegetatively
  
• Herbicides and mechanical methods may provide effective control