Aristea

General description

Evergreen perennial with woody rhizomes. Leaves are < 40 cm long, erect and often in a flattened fan. Flowers are blue and borne in clusters of 5-7. Capsules are dehiscent and three-sided, with dark red-brown seeds.

What you need to know

To help protect our environment:

• You must not breed, distribute, release or sell aristea. As aristea is a National Pest Plant Accord species, these restrictions apply within the Auckland region and across the whole of New Zealand.
• You must not plant aristea 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 aristea 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.

Habitats

Open and disturbed sites, roadsides, forest, scrubland, coastlines, herbfields, rocky and bare sites.

Dispersal

Seeds dispersed by water. Vegetative spread from rhizomes, dispersed by water. Human-mediated dispersal through contaminated soil on footwear and machinery.

Impact on environment

Forms dense stands, preventing native seedling establishment. May facilitate introduced shrub, vine and grass succession in forests.

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: All parts.

Disposal options: Compost in a composting weed bag or remove to greenwaste or landfill.

Biocontrol

Biocontrol is currently not available for this species.

Community agrichemical control recommendations

Basic Growsafe certified:

For small infestations: Foliar spray with 3g metsulfuron-methyl plus 150ml glyphosate per 10L of water.

Certified Handler/Experienced agrichemical user:

For medium to large infestations: Foliar spray with 3g metsulfuron-methyl plus 150ml glyphosate per 10L of water and 10ml penetrant.