Quick Facts

Quick facts

• Common Thornapple (Datura stramonium) is a robust, bushy, annual herb that grows to 1.2 m high and has bright green leaves and white or lilac tubular flowers.
• It is found widely in subtropical to temperate areas of Australia and occasionally in tropical and semi-arid areas.
• The whole plant is toxic to stock and people, with the seeds being the most toxic part.
• It is spread by seeds, often as a contaminant of crop seed, but also in mud on vehicles and by water).
• It is found in highly disturbed sites such as irrigated crops and pastures, waste land, stock yards and river banks .

What Does It Look Like?

What is it?

Common Thornapple (Datura stramonium) is a robust, bushy, annual plant that grows to 1.2 m high but may flower when only 0.2 m high. The stems are green, sometimes purple-tinged or entirely purple. The leaves are alternately arranged along the stem, stalked, bright green, oval to trowel-shaped widest below the middle), mostly 80–160 mm long and 40–100 mm wide (sometimes up to 300mm long and 200mm wide). They have a few triangular lobes along each margin with these lobes also bearing smaller angular teeth.  

The flowers are borne singly in the branch forks; they are shortly stalked, 60–85 mm long, white or lilac, trumpet-shaped, with 5 broad, short rounded-triangular lobes each ending in a narrow tip. There is a tubular, green covering (calyx) extending for about half of the total flower length from the base; it is angular and 5-toothed. 

Common Thornapple has capsular, prickly fruits, held erect on the plant. At maturity, the fruit body is egg-shaped, sometimes narrowly so, 20–45 mm long, with 100–200 more or less slender spine-like prickles, of slightly different lengths but evenly distributed; longer prickles 6–10 mm long, sometimes up to 16 mm long. The capsules open up evenly into 4 segments, sometimes only partly so, shedding a large number of seeds. The seeds are D-shaped, pitted, usually black, sometimes grey or grey-brown, 2.5–4.5 mm long. ( Haegi 1976; Purdie et al. 1982; Stanley & Ross 1986).

For further information or assistance with the identification of Common Thornapple contact the herbarium in your state or territory.

Flower colour

White or lilac

Growth form (weed type/habit)

Robust, bushy, annual herb

Where it currently grows? Preferred habitat

Common Thornapple prefers open disturbed habitats usually on fertile soils, including cultivated (often irrigated) paddocks, urban wasteland, roadsides and rail reserves, as well as along watercourses in drier areas. Soil can be sandy, loamy or clayey (AVH 2021).

Are there similar species?

Common Thornapple is somewhat similar to Fierce Thornapple (Datura ferox) which also has erect capsules that split into 4 valves, but Fierce Thornapple has shorter flowers and capsules with much larger and fewer prickles (only 40-60 per capsule), and larger seed (Purdie et al. 1982). It can easily be distinguished from all the other Datura species found in Australia because they all have capsules that are nodding or hang down when ripe and also break open unevenly (Haegi 1976).

Why Is It A Weed?

What are its impacts?

Agriculture: Common Thornapple is an important agricultural weed. It is poisonous to stock because of the presence of a number of toxic alkaloids. The seeds are the most poisonous part of the plant. Stock do not generally graze the plants because of their bitter taste and prickly seed pods, but are usually affected when they eat contaminated hay, chaff and silage.

Human impacts: Children are also known to have been poisoned after eating the seeds (Parsons & Cuthbertson 2001; Department of Agriculture and Food 2008).

Native ecosystems: Common Thornapple competes strongly with many crops (Parsons & Cuthbertson 2001) and may invade native ecosystems, especially along watercourses.

How does it spread?

Common Thornapple is dispersed by seed, often as a contaminant in crop seed, when it may be transported thousands of kilometres by road or rail. Seeds are also dispersed by water (because they float), or they may be spread in mud attached to vehicles or machinery (Parsons & Cuthbertson 2001).

What is its history in Australia?

Common Thornapple is thought to have been present in Sydney by 1804, although this is not certain. It was growing in Adelaide by 1839. It is thought to have been accidentally introduced as a contaminant of agricultural seeds (Parsons & Cuthbertson 2001).

How To Manage It?

Best practice management

Non-chemical control: Mechanical removal of Common Thornapple plants is effective for small infestations. Large stands on cropping land should be removed by ploughing or tilling the soil. Follow-up will be needed to remove seedlings that germinate from soil-stored seed in subsequent seasons.

Chemical control: Small plants are susceptible to herbicide, but this treatment may be ineffective for mature plants. (Parsons & Cuthbertson 2001). Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au 

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Common Thornapple is an annual plant. Flowers may be produced when the plant is only 2-5 weeks old. It flowers and fruits throughout the summer and autumn, but is generally killed by frosts in early winter (Parsons & Cuthbertson 2001).

Where Is It Found?

Which states and territories is it found?

Found in all Australian states and in the ACT but not in the NT.

What areas within states and territories is it found?

Common Thornapple is naturalised in south-western Western Australia; in temperate and semi-arid South Australia; fairly widely in Victoria but especially in central and eastern parts; in temperate, subtropical and semi-arid parts of New South Wales; fairly widely in the settled parts of Tasmania; principally around greater Canberra in the Australian Capital Territory; and along the Great Dividing Range in Queensland, in subtropical parts from the Gold Coast to Rockhampton, with a somewhat separate tropical occurrence from Townsville to Cairns (Purdie et al. 1982; Parsons & Cuthbertson 2001; AVH 2021).

Where does it originate?

The native area of occurrence of Common Thornapple is the southern USA and Mexico (Symon & Haegi 1999).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

NT (not to be introduced), TAS, VIC, WA

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Datura stramonium

Other scientific names (synonyms)?

• Datura inermis Jacq.
• Datura stramonium L. var. stramonium
• Datura stramonium var. tatula (L.) Torr.
• Datura tatula L.

Does it have other known common name(s)?

Jimson weed