Family: Malvaceae
Ceiba speciosa, commonly known as the floss silk tree, is a striking ornamental tree native to South America, particularly Brazil, Argentina, and Paraguay. It is best known for its distinctive green trunk covered in stout, conical spines and its large, showy pink flowers that bloom in late summer to fall when the tree is often leafless. The flowers are followed by woody seed pods filled with silky fibers, or “floss,” that surround the seeds. In landscapes, floss silk trees are valued for their dramatic appearance, drought tolerance once established, and ability to provide seasonal interest. They are commonly planted as shade or accent trees in parks, along streets, and in large gardens.
At this time, Ceiba speciosa is considered a low-risk species and is generally safe for cultivation. Although it produces seeds that can disperse short distances, it is not known to aggressively spread or form self-sustaining populations in Hawaiʻi or other tropical island environments. Seedlings typically require open or disturbed sites to establish and do not readily invade intact native ecosystems. When planted thoughtfully and monitored, the floss silk tree poses minimal ecological threat, making it a suitable ornamental choice where space allows.
High Risk Traits:
- Rapid growth rate, allowing it to establish quickly once planted
- Large size at maturity, which can outcompete nearby vegetation for light and space
- Produces numerous lightweight seeds, potentially capable of dispersal by wind
- Tolerance of a range of soil types and urban conditions, increasing establishment success outside cultivation
- Lack of specialized pests or diseases in introduced ranges, which may reduce natural population control
- Produces spines – trunk covered with sharp prickles, which could cause injury.
Low Risk Traits:
- Primarily cultivated as an ornamental, with spread usually limited to planted landscapes
- Not currently known to be invasive or widely naturalized in Hawaiʻi or other Pacific islands
- Long juvenile period before reproduction, slowing population expansion
- Seedlings generally require open, disturbed sites, reducing establishment in intact native ecosystems
- Does not form dense monocultures or aggressively displace native plant communities
