Several nut bearing exotic woods are very sensitizing. Cashew ( laquer tree) and Mango are two in particular. They have high levels of urushiol. This is the same toxin as in Poison ivy.
Trees are really neat when you find out about the chemistry that evolution has evolved to protect the seeds and tree. Take the nectarine, peach, and the almond tree - same family. The fruit looks pretty much the same. The nectarine and peach have edible flesh, but the seed ( it isn't a nut) is toxic. The Almond has an edible seed, but toxic flesh. There are very bitter alkaloids and even a low level of cyanide in the inedible parts of these related trees.
Another neat thing is that from 50,000 until 10,000 years ago,certain trees in north-east North America had big strong thorns on them, similar to honey locust. Before then, they didn't have the thorns. They mutated to grow these spikes in order to keep browsing animals from tearing the tree up while eating the leaves. Then, around 10,000 years ago, the spikes disappeared. The reason was that the primary animal that browsed on them was the mammoth. No mammoth - no need for spikes. The spikes disappeared in less than a thousand years, pretty much like the mammoth did.
The other mammoth tree is the Osage orange. During the same 50,000 to 10,000 year period, these trees were widespread over North America. They dwindled in range as the mammoths dwindled. Now, they are mainly in Texas. The fruit had evolved to be eaten by mammoths. The flesh was soft and tasty to the mammoth, but the nut was too hard to chew and would not digest. The tough seed was swallowed whole to be planted many miles away from the parent tree in a nice pile of fertilizer. The roaming herds of mammoth spread these trees everywhere - uphill, downhill, across mountains and plains. Now that the mammoth are gone, the trees are restricted to being propagated by the seeds floating on storm waters or rolling downhill. That is the reason they tend to grow in hedge rows and lines.
