Am seeing this weed everywhere at the moment. This patch stretched between the roundabout on Anzac Parade and back toward Civic for hundreds of metres. Seems to be coming in on imported soil.
About three years ago several people were poisoned by eating spinach contaminated with datura (common thornapple). The weed is commonly brought to Canberra by contaminated landscaping soil. I don't know if there are any biosecurity rules to stop this. I have seen it growing alongside vegetables so it would be possible for it to end up in a salad. Symptoms of poisoning include: thirst, dilated pupils, high temperatures, weak or rapid pulse, incoherence or hallucinations, vomiting, breathing problems, convulsions. Wash your hands if you are pulling it out.