Horse nettle

Horse nettle is a perennial herbaceous plant that grows up to one metre tall and dies back over winter.

Description

• Stems and leaves are covered with 5mm long, straw coloured prickles.

• Leaves are dull green with wavy edges.

• Stems become woody with age.

• Flowers are white/violet with yellow centres, star-shaped, and grow in clusters. Flowers appear between January to March.

• Fruit are green berries, turning yellow and wrinkled with maturity.

• Taproot grows deep and has spreading rhizomes.

• Seeds are dispersed by mammals, wind, and water and vegetatively via rhizomes

• Habitats include disturbed areas, roadsides, and pasture lands, as well as maize paddocks.

What you need to know

Horse nettle is extremely invasive and difficult to control.

All parts of the plant are poisonous to humans and animals.

Ingesting any of the plant can cause fever, headache, scratchy throat, nausea, vomiting, and diarrhoea. Ingesting the fruit can cause abdominal pain, circulatory and respiratory depression, or even death.

If you think someone or an animal has ingested horse nettle, contact your local poison information centre on 0800 POISON (0800 764 766) or your local vet.

Management approach

Horse nettle is declared an unwanted organism by the Ministry for Primary Industries (MPI) because it is capable of causing harm to the natural environment, physical resources or human health in Aotearoa/New Zealand.

These species pose a high risk to our environment, economy, recreation, and cultural values.

Rules

Any species declared a pest cannot be sold or be in a place where plants are being sold. Pest plants cannot be propagated, bred, multiplied, communicated, released, caused to be released, or otherwise spread.

Control

Do not attempt to undertake control of horse nettle yourself. Report any sightings to us.