Family: Asphodelaceae
An evergreen, perennial monocot that invades intact forests. As the common name suggests, New Zealand Flax, this plant is native to New Zealand. Introduced to Hawaiʻi in the late 1800s as a potential fiber crop, it has spread from initial plantings and has naturalized in Moloka’i and Kauaʻi. A large infestation has established in the Montane Ohia-Uluhe rainforest of Kamakou Preserve at approximately 3750 ft in Moloka’i. The main population, which is located just above Pu’u Kolekole, thrives in a very wet flat area with poor drainage. Although present in cultivation, New Zealand flax should be avoided. Oceania, Chili, and the United Kingdom list this plant as invasive. New Zealand Flax is a ‘no grow’ species for the Big Island Invasive Species Committee (BIISC) Plant Pono program.
Description and Dispersal:
- An evergreen, perennial monocot that can grow up to 13? tall and 7? wide
- Leaves are ridged, sword-shaped and erect- ranging in color from bright green to bronze and purple
- Red or yellow tubular flowers arise in bunches extending up to 12' tall
- Fruit is a 3-angled capsule up to 4' long, containing 10,000 viable seeds per inflorescence
- Seeds are wind dispersed
High Risk Traits:
- Naturalized in Hawaii and Spain
- Environmental weed in Hawaii (top 10 priority)
- Forms dense, exclusionary thickets
- Reproduces vegetatively via rhizomes; resprouts after uprooting
- Produces >10,000 seeds per inflorescence
- Wind-dispersed winged seeds
- Self-compatible
- Hybridizes with P. colensoi
- Deliberately spread by humans (fiber crop)
- Tolerates mutilation; requires repeat herbicide
- Wide soil tolerance (sand, poor drainage, peat)
Low Risk Traits:
- Lacks spines, toxins, or allelopathy
- Prefers full sun (not shade tolerant)
- Takes 6–7 years to flower from seed
- No seed bank
