What good are thorns? Okay, we know why they are on raspberries and blackberries and such, it’s to keep things from eating all the berries before they can ripen and make new plants. Even asking the question about those berries is kind of silly . . . .
What about real thorns? I mean the really nasty ones that stick out from cute little fan palm trees. I have a friend whose landscaper put some of those right next to the
patio. A strange place for a plant with thorns like needles up to 3 inches (that’s 7-8 cms.) long. I am sure native peoples used them for sewing and fish hooks but what are they doing next to the patio? Seems like they are lying in wait for the unsuspecting guest or maybe a pet. Not in my yard, for sure.
Then there are the other trees with spines. The cedro is one. The spines are thick and conical and very rough. Or the ceiba with warty spines. Then there is the palo verde and the white cedar (hura crepitans) and a bunch of other trees, large and small, that make an outing into the local patches of jungle such a treat. If you slip and start to fall, there are certain trees that you should not grab. Better to hit the ground than get some of these spines in your hand.
So, trees have spines for protection too, but why? Most of these spines start at ground level and go up 3 to 5 meters (that would be 10 to 17 feet) and then peter out. Why do these trees need protection? For the answer, we have to look into the distant past.
Until about 11,000 years ago there were megafauna roaming through what is now Costa Rica. How do we know? A bone from the extinct camelop (a camel-like animal) was found during digging of the new section of the Panama Canal. There are, of course, many other examples in the fossil record.
So, suppose you are a ceiba tree and you don’t want a josephoartigasia chewing on you. Just a rodent? Think again; the josephoartigasia was the size of a cow. How do you protect yourself from an animal the size of a cow that wants to chew on your trunk? You grow spines, of course; nice big ones. Or you grow warty bark that discourages chewing.
Well, the megafauna are gone but the spines and warts persist. Perhaps one day they will be gone as well. Until then, be careful what you reach for. Even trees can bite.