The "Magic" tree
 

Don't forget about Anacardiaceae.

I have a story about that family. 50 years ago, while on a trip to Israel, I
developed a poison-ivy type rash on my arm. I was very puzzled, since I knew
p.i. and its relatives are strictly New World plants. i went to a local doctor,
who was equally puzzled. He gave me some anti-itch cream & eventually it went
away. Years later I read somewhere that some people are allergic to the sap of
the mango tree, a member of the Anacardiaceae. While eating mangos in Israel, I
got some of the sap from the skin of the mango on my arm. Since then, if I want
to eat a mango, I have someone wash it first, and I never had any trouble
since.
And if you didn't think Pistachios are related to Sumacs, just try smelling
them while pruning.

The Euphorbiaceae s.l. (to which Hippomane belongs) contain some more
species with a reputation for being poisonous,

Euphorbia, especially the sap, is said to be a co-carcinogen with tobacco. So,
if you must smoke, don't do it while pruning your Crown-of-Thorns.

Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)