DISTRIBUTION:
Possibly originating in tropical America, it is now widely distributed in South Africa, especially in disturbed soil, like seasonal river courses, cultivated lands and along roadsides.
BOTANICAL DESCRIPTION:
General: A large-leafed, robust annual weed. The most characteristic feature is its hardened spiny fruit capsules, which contain a very large number of small black compressed kidney-shaped seeds.
TOXIC PRINCIPLE:
The seeds are the most poisonous part of D. stramonium and contain the alkaloids atropine and hyoscine.
MECHANISM OF ACTION:
• These alkaloids are parasympatholytic compounds.
SYSTEMS AFFECTED:
Central nervous system.
CLINICAL SIGNS:
• Humans are exceptionally susceptible to poisoning.
• Livestock is not often affected; horses are more commonly the victims
of Datura poisoning.
• Rabbits are resistant, due to atropine esterases.
• Clinical signs include
- mydriasis and cycloplegia,
- tachycardia,
- dryness of the mouth,
- colic and tremors.
