Dave Poole wrote:

I've heard all manner of scare stories about Datura and its close
relative Brugmansia. Most of them are sensationalist in the extreme -
probably due to scant information being incompletely understood from
internet sources.

And partly because some US jurisdictions have banned them. A pretty
stupid thing to do since some species grow wild over there.

*Not* from internet sources - here's as much as I've needed to learn:
The 'poisons' are amongst a group of alkaloids collectively known as
tropanes. In Brugmansia, Datura & Mandragora, the 3 most notable are
hyoscyamine, atropine & solanine. In these plants, concentrations are
always greatest in the seeds and roots, which means those are the most
poisonous parts of the plant.

It is my understanding that the molecules of these alkaloids do not
easily pass through the skin and therefore only large quantities of
sap allowed to remain in contact for a long time would be likely to
have an effect. With the exception of the very old, very young and
those with extreme allergic tendencies, the worst effects of
'systemic' absorption are likely to be nausea, disorientation and
tiredness lasting for about 24 hours.

The smell of a bruised leaf is enough to put most people off eating the
plant. I can smell/taste it when ever I've been handling them.

As to the dangers of anyone (children especially) accidentally chewing
on the leaves etc. trust me, the taste courtesy of these alkaloids is
very bitter and acrid. No-one would willingly and innocently chomp
enough to make them dangerously ill. I once tried a half cm. square
of leaf and it made me want to throw up immediately.

The seeds are pretty good as natural rodent bait. They invariably claim
a few field mice in my greenhouse during the winter. Some are not killed
outright but meander round in circles or figures of 8.

I'm not suggesting for a moment that there's absolutely no danger from
these plants - chewing on seeds, smoking handfuls of leaves etc. will
make you exceptionally ill and can be fatal. But, they are not as
spectacularly toxic from casual contact as sensationalists would have
us believe. In this context, buttercups and bluebells are equally as
dangerous. When handling the plants, wash afterwards, don't include
the leaves in salad and don't try to make tsizanes from any parts. In
other words, use a bit of common sense and you'll be perfectly all
right.

I think that is true. There are lots of other toxic plants around but a
handful of the most notorious ones get most of the attention. And not
necessarily in proportion to the threat they pose.

Unfortunately these days common sense is in short supply and everything
is labelled with hazard labels. You should see the laboratory MSDS for
table salt, sugar or even pure water.

Regards,
Martin Brown