Family: Marattiaceae
Origin, Description & Uses
Ptisana salicina, commonly known as king fern, potato fern, or para, is a large tropical fern native to northeastern Queensland, New Zealand, and parts of the South Pacific. This striking fern forms massive clumps of arching fronds that can reach several feet in length, giving it a lush, prehistoric appearance well suited to shaded gardens and rainforest-style landscapes. It thrives in moist, humid environments with rich soils and is valued as an ornamental plant for its dramatic foliage and ability to create a dense tropical effect in gardens and botanical collections.
Risks & Threats
Although Ptisana salicina is not currently known to be naturalized in the Hawaiian Islands, it does possess traits that are cause for concern. Like many large ferns, it may spread through spores in favorable wet forest habitats, particularly in humid tropical environments similar to parts of Hawaiʻi. Dense fern growth could potentially compete with native understory plants for light, moisture, and space if it were to escape cultivation. Ongoing evaluation is needed to determine whether this species could negatively impact Hawaiʻi’s native ecosystems, and caution is recommended when planting it near natural areas.
High Risk Traits:
- Grows in regions with tropical climates
- Shade-tolerant
- Reproduces by spores and vegetatively by rhizome division
- Spores presumably dispersed by wind, and water
- Presumably produces prolific numbers of spores
- Gaps in ecological information reduces accuracy of risk prediction
Low Risk Traits:
- No reports of invasiveness or naturalization, and in decline within native range, but limited evidence of widespread introduction outside native range
- Unarmed (no spines, thorns or burrs)
- Palatable to pigs, goats and other browsing/grazing animals (contributing to decline within native range)
- Non-toxic
- Ornamental
- Propagation from spores reported to be difficult
