This is a seed pod from the deadly thorn-apple – I have abstained from having them in my garden up until now because of having small kids around.  They are a troublesome species and associated with a lot of words that I had to look up.

Wiki:  Due to the potent combination of anticholinergic substances it contains, Datura intoxication typically produces effects similar to that of an anticholinergic delirium (usually involving a complete inability to differentiate reality from fantasy); hyperthermia; tachycardia; bizarre, and possibly violent behavior; and severe mydriasis with resultant painful photophobia that can last several days. Pronounced amnesia is another commonly reported effect.

anticholinergic: a substance that blocks the neurotransmitter acetylcholine in the central and the peripheral nervous system
hyperthermia: elevated body temperature due to failed thermoregulation that occurs when a body produces or absorbs more heat than it dissipates
tachycardia: a heart rate that exceeds the normal resting rate
mydriasis: the dilation of the pupil, usually defined as when having a non-physiological cause
photophobia: a symptom of abnormal intolerance to visual perception of light
amnesia: a deficit in memory caused by brain damage, disease, or psychological trauma

And all that from a plant that is easily grown from seed. The plant I photographed was bought at our local supermarket – I noticed it  because it has its’ flowers standing up instead of hanging, which I think is much more attractive. It grows like a weed and produces flowers that fold open in the most delectable manner.