Thornapple

There are four types of invasive thornapples in Australia, all of them are a declared Class C weed under the name Datura spp.

One of those four, the longspine thornapple (D. ferox), is declared a declared Class A and Class C weed.

If you think you may have seen thornapple, or have this weed on your property, contact the Weed Management Branch immediately for assistance.

Thornapple - 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:

  • erect, branched, annual plant
  • grows to about 1m tall.

Thornapple - habit

Stems and branches

These features can identify the stems and branches:

  • stems are smooth.

Thornapple - stems and branches

Leaves

These features can identify the leaves:

  • lance or oval shaped
  • up to 15cm long
  • toothed margins and pointed lobes.

Thornapple - leaves

Flowers

These features can identify the flowers:

  • trumpet-shaped flowers
  • erect
  • white petals
  • 6 to 10cm long
  • Single flowers grow in the forks of the branched stems.

Thornapple - flower

Fruit and seeds

These features can identify the fruit and seeds:

  • round, spiny and green
  • 4 to 5cm in diameter
  • four compartments containing numerous brown to black kidney shaped seeds.

Thornapple - fruit and seeds

Similar looking plants

There are four similar looking varieties of thornapples; longspine, downy, hairy and native thornapple.

If you think you may have seen thornapple, or have this weed on your property, contact the Weed Management Branch immediately for assistance. 

There is no harm in controlling any of the latter three species and it is imperative that the longspine thornapple is controlled.

Impact

Thornapple can have all of the following impacts:

  • the fruits have alkaloids that are potentially toxic
  • there are records of pig, horse, poultry and human deaths
  • toxicity to stock varies
  • cattle appear to eat it without suffering any effects
  • competes with native plant species and reduced available food for native animals
  • has the potential to impact fire frequency and intensity.

Habitat and distribution

Thornapples are native to Central and South America and Mexico, and are also known to occur in Asia and North Africa.

It was introduced to Australia as a garden plant, and is still closely associated with human settlements in the Northern Territory. It has been used for medicinal purposes.

Thornapples prefer disturbed sites and fertile soils such as stock camps, around bores, stockyards and stables and along riverbanks.

Small infestations occur around bores, stockyards, and stables in the Katherine, Victoria River and Gulf districts.

Control

If you think you may have seen thornapple, or have this weed on your property, contact the Weed Management Branch immediately for assistance.

Chemical control

The best time to treat thornapple is from December to March. Below is a list of treatment methods that can be used.

Chemical and concentration Rate Situation, method and notes
2, 4-D amine 625g/L
Various trade names
320ml / 100 L Seedling or adult (individuals or infestation):
Foliar spray - apply when actively growing
Glyphosate 360g/L
Various trade names and formulations
15ml / 1 L Seedling or adult (individuals or infestation):
Foliar spray - apply when actively growing
MCPA 340g/L + Dicamba 8 g/L
Various trade names
350ml / 100 L Seedling or adult (individuals or infestation):
Foliar spray
Fluroxypyr 200g/L
Various trade names
1 L / 100 L Seedling (individuals or infestation):
Foliar spray - Uptake® spraying oil required
Fluroxypyr 333g/L
Starane® Advanced
450ml / ha
(boom)
Seedling (individuals or infestation):
Foliar spray - Uptake® spraying oil required
Boom application - apply when actively growing

Non-chemical control

Hand pulling and grubbing

Weeds, including their roots, are physically pulled out of the ground by hand or using hand tools. 

This is an effective method of control for individual weeds and recent outbreaks that haven’t released seeds yet, but it requires a lot of labour.

Last updated: 27 June 2017