Datura inoxia (Downy Thorn Apple)

Scientific name

Datura inoxiaMill.


Datura meteloides DC. ex Dunal

Common names

Downy thorn apple




Central and South America and the West Indies.

Naturalised distribution (global)

Locations within which Datura inoxia is naturalised include Taiwan and southern  Africa.

Introduced, naturalised or invasive in East Africa

This species has not been recorded in the region but could become an invasive species if introduced.


Weed of degraded areas, farmland, roadsides.


Datura inoxia is an annual to perennial herb to up to 1 m high with a spreading crown about 2 m in diameter.

The stems of D. inoxia and its leaves are covered with short and soft greyish hairs that give the whole plant a greyish appearance.

Leaves are simple, elliptic, entire margins, with conspicuous pinnate venation alternately arranged along the stem.

D. inoxia bears white tubular (trumpet) flowers that have green veins, 12-19 cm long, stigma well above anthers. Some people find the flowers fragrant at night, when the plant is blooming.

The fruit is an egg-shaped spiny capsule with numerous slender spines, about 5 cm in diameter. All spines nearly the same length (up to 1 cm long). The capsule stalk bends sharply downwards. Capsules produce brown seeds, 4-5 mm long. When ripe, the capsule splits open, dispersing the seeds.

Reproduction and dispersal

Spread by seed and vegetative cuttings. The spiny capsule is also dispersed on the fur of animals.

Similar species

Datura ferox and Datura stramonium (common thornapple) produce erect capsules on straight stalks which contain black or grey seeds.

Datura leichhardtii, Datura metel, Datura inoxia and Datura wrightii can be differentiated from these two species as their capsules are held on a curved stalk, and they produce brown or yellow seeds.

D. ferox can be distinguished from D. stramonium by its capsule which, has about 40-60 spines of variable length.

D. ferox flower is shorter (4-6 cm long) compared to the flower of D. stramonium which is longer, i.e. up to 10 cm long.

Brugmansia species may be confused with Datura species. Brugmansias long-lived (perennial) while daturas are annual. Both plants have a trumpet shaped flower; but those of brugmansias point downwards while datura's flowers most often point upward. Brugmansias emit a sweet fragrance while datura's fragrance can be described as spicy or lemony.

Economic and other uses

Datura inoxia can be grown as an ornamental plant. However, this use cannot compensate for this plant's overall negative impacts.

Environmental and other impacts

Datura inoxia readily escapes from gardens where it is being cultivated. All parts of Datura plants contain dangerous levels of poison and may be fatal if ingested by humans and other animals, including livestock and pets. D. inoxia has been listed as a noxious weed in South Africa (prohibited plants that must be controlled. They serve no economic purpose and possess characteristics that are harmful to humans, animals or the environment) and several Australian states. In some countries of the world, it is also prohibited to buy, sell or cultivate Datura plants.


The precise management measures adopted for any plant invasion will depend upon factors such as the terrain, the cost and availability of labour, the severity of the infestation and the presence of other invasive species. Some components of an integrated management approach are introduced below.

The best form of invasive species management is prevention. If prevention is no longer possible, it is best to treat the weed infestations when they are small to prevent them from establishing (early detection and rapid response). Controlling the weed before it seeds will reduce future problems. Control is generally best applied to the least infested areas before dense infestations are tackled. Consistent follow-up work is required for sustainable management.

Datura inoxia can be managed by digging it up or otherwise removing it. It can also be sprayed with a suitable herbicide. When using any herbicide always read the label first and follow all instructions and safety requirements. If in doubt consult an expert.

The editors could find no information on any biological control agents for this species.


Not listed as a noxious weed by the state or governments in Kenya, Tanzania and Uganda.


Datura inoxia typically produces a complete inability to differentiate reality from fantasy (delirium, as contrasted to hallucination); hyperthermia; tachycardia; bizarre, and possibly violent behaviour; and severe mydriasis with resultant painful photophobia that can last several days. Pronounced amnesia is another commonly reported effect. There can easily be a 5:1 variation in toxins from plant to plant, and a given plant's toxicity depends on its age, where it is growing, and local weather conditions. These wide variations make Datura exceptionally hazardous to use as a drug.


Henderson, L. (2001).  Alien weeds and invasive plants. A complete guide to declared weeds and invaders in South Africa.  Plant Protection Research Institute Handbook No. 12, 300pp. PPR, ARC South Africa.

Parsons, W.  and Cuthbertson,  E. (1992). Noxious Weeds of Australia.  pages 595-600.


Agnes Lusweti, National Museums of Kenya; Emily Wabuyele, National Museums of Kenya, Paul Ssegawa, Makerere University; John Mauremootoo, BioNET-INTERNATIONAL Secretariat - UK.


This fact sheet is adapted from The Environmental Weeds of Australia by Sheldon Navie and Steve Adkins, Centre for Biological Information Technology, University of Queensland. We recognise the support from the National Museums of Kenya, Tropical Pesticides Research Institute (TPRI) - Tanzania and Makerere University, Uganda. This activity was undertaken as part of the BioNET-EAFRINET UVIMA Project (Taxonomy for Development in East Africa).


BioNET-EAFRINET Regional Coordinator: [email protected]