On 24/10/2019 18:58, Nick Maclaren wrote:
In article ,
Martin Brown wrote:

The point is that, allergies and damage to mucous membranes aside,
any plant found 'in the wild' in the UK can be handled and even tasted
without serious risk of death or permanent injury. The same is not
true for tropical plants, including those grown in conservatories,
greenhouses etc.

I think hemlock (Conium maculatum) might be a bit borderline in this
respect and it is quite common in suitably damp hedgerows in season.
It seems to follow the loathsome oilseed rape around somehow.

No, though it is claimed to be. I looked it up, and you need more
than a taste to kill yourself.

I think that is also true of Amanita Phalloides (aka destroying
angel/death cap) too - snag is it apparently tastes rather good.
LD50 is about half a mushroom.

I have eaten the Amanita Caesarea in Italy and it is excellent if a
little unnerving to eat a safe member of such a toxic class of fungi.

https://en.wikipedia.org/wiki/Amanita_caesarea

Colchicums are also naturalised in places and pretty toxic.

I believe the same applies here.

Probably although I don't fancy trying it.
Lovely flowers this time of year and trouble free.

The point is that toxins cost the plant a lot of energy to produce,
so are more evolutionarily effective for tropical plants. Fungi
have a very different kind of metabolism.

A good heuristic I was taught in jungles is that milky sap is usually
dangerous and clear sap might well be potable (there are exceptions).
Lettuce is the obvious counterexample of common UK vegetables.

Certainly true that in places where there is serious water stress and or
grazing the plants have evolved astonishingly sophisticated chemical
weapons. Fortunately very few have mastered organofluorine chemistry -
things like gifblaar in the Transvaal and some others in Australia.

https://en.wikipedia.org/wiki/Dichapetalum_cymosum

Of the succulent plants some Tylecodons are wear gloves when handling
and some of the nastier toxic Euphorbias gloves, goggles or face mask.

https://en.wikipedia.org/wiki/Tylecodon
https://en.wikipedia.org/wiki/Euphorbia_virosa
http://pza.sanbi.org/euphorbia-virosa

The latter is a handsome plant when small and I have grown it in the
past with red new spine pairs and bright green body. Not for novices.

It is slightly surprising that we can safely eat soya given how
disruptive the hormone mimics in it are to rodent reproduction.

https://www.scientificamerican.com/a...nes-genistein/

Most of the things we associate as interesting tastes and narcotic
effects are actually natural insecticides, fungicides or sunscreens.

--
Regards,
Martin Brown