Arum lily

General description

Clump-forming rhizomatous perennial herb < 1.5 m tall. Leaves are arrowhead-shaped, < 30 x 60 cm, dark green, leathery and usually glossy. Flowers are yellow, borne in spikes < 9 cm tall and surrounded by white spathe in winter – summer. Fruits cluster on the lower part of spike and are green/yellow ripening to orange. Note: The National Pest Plan Accord RPMP status only applies to the 'Green Goddess' cultivar.

What you need to know

To help protect our environment:

• You must not breed, distribute, release or sell arum lily within the Auckland region. As the cultivar ‘Green Goddess’ is a National Pest Plant Accord species, these restrictions also apply across the whole of New Zealand for this cultivar.
• You must not plant arum lily within the Auckland region, unless you are transferring an existing plant on your land to another location within the boundaries of the same property.
• You must destroy any arum lily on land that you occupy if it has been planted in breach of the above rules and you are directed to do so by an authorised person.

This applies to all cultivars. Please note the cultivar Green Goddess is already banned from sale nationally, including Auckland.

Habitats

Wetlands, riparian margins, drains, damp ground, pasture, forest, coastal sandy habitats.

Dispersal

Seeds dispersed by birds, livestock and water. Vegetative spread from rhizomes, exacerbated by feral pigs. Human-mediated dispersal through soil movement, dumping of garden waste and deliberate plantings.

Impact on environment

Forms dense patches, excluding other plants in wetlands, riparian margins and damp forest gullies. Displaces valuable pasture species and is toxic to livestock.

Control

Site management

Follow up treated areas 3 times per year. Encourage natural regeneration of native plants or replant treated areas where possible after 2-3 treatments to establish dense ground cover and minimise reinvasion.

Recommended approaches

Physical control

Method: Dig out.

Plant parts requiring disposal: Rhizomes.

Disposal options: Small amounts can be rotted in a covered water barrel or remove to greenwaste or landfill.

Biocontrol

Biocontrol is currently not available for this species.

Community agrichemical control recommendations

No qualifications: For small infestations on terrestrial sites, cut stump and paste freshly cut base of stems with metsulfuron gel.

For small infestations on aquatic sites, cut stump and paste freshly cut base of stems with double strength glyphosate gel.

Basic Growsafe certified: For medium infestations on terrestrial sites, cut stump and spray freshly cut base with 1g metsulfuron-methyl per 1 L of water.

For medium infestations on aquatic sites, cut stump and spray freshly cut base with 250ml glyphosate green per 1 L of water.

Certified Handler/Experienced agrichemical user: For large infestations on terrestrial sites, cut stump and spray freshly cut base with 1g metsulfuron per 1 L of water.

For large infestations on aquatic sites, cut stump and spray freshly cut base with 250ml glyphosate green per 1 L of water.