Under The Tree When It Rains

In my younger days, I have experienced seeking shelter from the rain under the tree. But not all trees can shield you from the rain. Choose one with big leaves like mango or jackfruit. For wood trees, the acacia has very small leaves that wouldn’t deflect the rain. When staying in a tent, it is also advisable to pitch your tent under a tree to at least have some protection when it rains hard. Modern tents have thin fabric that although water-proof can have leaks in the zipper area. When under a tree, the leak is not much.

 

Nope
Never use a tree for shelter or to camp under!
Too many people get killed by falling branches or lightning strikes

 

Exactly what Arkane said: never hide under a tree during a storm! Everybody should know that.
It's just a random chance that the lighting could hit the tree, it happens a lot for various reason. First of all, trees are electrical conductors. They are full of water and salts inside them, plus they might be wet when it's raining. And as you know water and electricity is a dangerous combination...
Plus they are nature's lighting rod: they are high and as I said are conductors, therefore a good option for the lighting to "choose".
Stay away from tress!