Physic nut

Physic nut is a declared Class A and Class C weed.

Another name for this plant is Jatropha curcas.

If you think you may have seen physic nut, or have this weed on your property, do not attempt to control it. Contact the Weed Management Branch immediately for assistance.

Physic nut - infestation 

Identification

You should use this as a guide. There may be other plants or weeds that look similar.

If you are unsure, contact the Weed Management Branch.

Habit

These features describe the habit of this plant:

  • drought resistant, erect perennial shrub
  • up to 4m high
  • toxic to humans and animals.

Physic nut - habit 

Stems and branches

These features can identify the stems and branches:

  • grey bark
  • spreading branches
  • thick, sappy stems.

Physic nut - stems and roots 

Leaves

These features can identify the leaves:

  • smooth, dark green
  • rounded
  • three to five lobes
  • five prominent veins that run across the leaf’s surface.

Physic nut - leaves 

Flowers

These features can identify the flowers:

  • yellow-green
  • form in clusters on stalks in upper axils.

Physic nut - flowers 

Fruit and seeds

These features can identify the fruit and seeds:

  • fruit pods change from green to dark brown when ripe
  • split into three sections
  • each section releases one to three seeds
  • seeds are black, oblong and toxic
  • 2cm long and 1cm wide.

Physic nut - fruit and seeds 

Similar looking plants

The following plant species look similar to physic nut:

Impact

Physic nut can have all of the following impacts:

  • seeds are toxic to humans, goats, sheep and calves
  • economic impacts from death of stock animals overseas
  • out-competes native plants in drought conditions
  • forms monocultures and dense impenetrable thickets
  • excludes native flora and fauna and disrupts ecosystem processes
  • may interrupt traditional owner’s cultural connections with the land and inhibit recreational activities such as hunting, camping and bushwalking.

Habitat and distribution

Physic nut is native from Mexico to Paraguay and to the Caribbean islands and is thought to have been introduced to Asia and Africa by Portuguese merchants in the 18th century. 

It used to be considered a garden ornamental, but it has since been declared as a weed in the NT and in Queensland where it has now naturalised.

Two physic nut infestations have been recorded in the Northern Territory; one at Mt Wells near Pine Creek and the other at Kapalga. Both these infestations have been eradicated. It is drought resistant and will grow under a wide range of climatic and soil conditions, but is often found in disturbed areas.

Control

If you think you may have seen physic nut, or have this weed on your property, don't attempt to control it. Contact the Weed Management Branch immediately for assistance.

Last updated: 27 June 2017