Naturally when I saw this, I thought about going for a repeat.
This is (I believe) Datura stramonium which like many toxic and/or hallucinogenic plants has the benefit of many a common name including (per Wikipedia) Jimson weed, devil's trumpet, devil's weed, thorn apple, tolguacha, Jamestown weed, stinkweed, locoweed, datura, pricklyburr, devil's cucumber, hell's bells, moonflower and, in South Africa, malpitte and mad seeds. My favourite common name for this is Devil's Snare because a) that's just a freaking awesome name; and b) Harry Potter!! (NB - Rowling's representation does not appear to be botanically accurate). Harry Potter aside, the names above general hint at this thing having some nasty properties and the one name that really doesn't is the one that reveals its true "potential".
The James-Town Weed (which resembles the Thorny Apple of Peru, and I take to be the plant so call'd) is supposed to be one of the greatest coolers in the world. This being an early plant, was gather'd very young for a boil'd salad, by some of the soldiers sent thither to quell the rebellion of Bacon (1676); and some of them ate plentifully of it, the effect of which was a very pleasant comedy, for they turned natural fools upon it for several days: one would blow up a feather in the air; another would dart straws at it with much fury; and another, stark naked, was sitting up in a corner like a monkey, grinning and making mows [grimaces] at them; a fourth would fondly kiss and paw his companions, and sneer in their faces with a countenance more antic than any in a Dutch droll.
In this frantic condition they were confined, lest they should, in their folly, destroy themselves — though it was observed that all their actions were full of innocence and good nature. Indeed, they were not very cleanly; for they would have wallowed in their own excrements, if they had not been prevented. A thousand such simple tricks they played, and after eleven days returned themselves again, not remembering anything that had passed. – The History and Present State of Virginia, 1705
Pretty ropey scenario to find yourself in albeit box office botany for a blog like this.
These are growing in a small clearing in a field opposite my house (there are at least 7) and I'll keep an eye out for open flowers for you all. It's worth noting this is really a tropical plant (albeit one we have no idea of the home range of) and in my British climate will be an annual weed. Apparently in a warm summer it will turn up pretty widely in the UK, less so if it's cold. In both its possible evolutionary birthplaces, North America and South Asia, Datura stramonium was used as a mystical sacrament (the name Datura is derived from Hindi) but as the above suggests, for anyone who found this blog googling for hallucinogenics this plant is a stone-cold killer and really, really not to be toyed with if you like your mind.