Along the beaches, as in other parts of the Caribbean, you will find the big beautiful Machineel trees. They are usually accompanied by warning signs, but you should learn to recognize and avoid them. I am told they produce nasty boils if the sap comes in contact with your skin (so don't stand under them when it rains!!) and the fruit and leaves are apparently deadly. They are quite distinctive, however, so once you know what they look like, just stay away!
Along the beach these trees usually having warning signs on them. Your skin may become irritated. They look like a huge ficus tree. Don't stand under it either when it's raining.