“One of the first palm trees in Xcalak you’ll meet, is the coconut palm. And unless you’re an expert on the Arecaceae plant family, you probably assumed that because it’s called a “palm tree” that it’s a tree.
A palm tree is actually a type of grass. Two key differences:
a palm tree does not create rings as it grows – it’s yearly growth isn’t marked on the tree
a palm tree does not grow bark – it’s basically the same on the inside as the outside
Calling a palm tree “palm grass” is technically correct. But with a trunk, a crown of leaves, and everyone in the English-speaking world calling them “palm trees”, don’t change your vocabulary now.”
From Xcalak Mexico Site: (http://xcalakmexico.com/shocking-facts-about-palm-trees/)