Nature Experience – Thorns

Ouch! Once again, one of them found me, worked its way past the defenses of long pants or gloves to bite into my skin and hang there. Its another dang thorn.

Why do plants have thorns? How can we enjoy the scent of bright flowers, or the sweet nectar of berries and other fruits if it hurts us to get close?

I can’t count how many times thorns have made my life miserable. From scratches from berry plants and rose bushes to thorns from cockle burrs growing in the grass (I love to go bare foot) it is impossible for me to make it a full week, much less a month, without pricking myself on something.

So, why do so many of the plants we love have thorns? Turns out, there is a very good reason. Thorns are one of the very few defenses a plant has against predators. And face it, when we pluck a berry, or a rose, we are taking away what might eventually become a seed, the only way a plant has to guarantee the survival of its kind.

Grazing animals learn to avoid plants that have thorns, preferring, usually, to eat other things that don’t bite back.

A botanist (plant scientist) will tell you that thorns have evolved from the stems of leaves, after the leaf itself has been lost. These stems become tough and woody and sharp to pierce the skin of anything that might come near to harm the plant. Sometimes, the thorns are actually attached to the leaves, like those of the holly plant.

Many of the plants we associate with thorns are members of the cactus family. An interesting fact: the spines of these plants have replaced their leaves, and are responsible for photosynthesis – the process by which the plant makes its food.

Thorns come in many different shapes, from long, hard thorns to soft ones barely visible until they have done their dirty work.

Take a walk around your yard. How many plants do you find that have thorns?
 
In my yard, I find a green briar vine, climbing the fence; a blackberry vine, threading its way through the undergrowth; a rose bush; and finally, a prickly pear cactus growing in a sunny, rocky section of my yard. Right now, that cactus is covered with beautiful yellow rose-like blooms. Needless to say, I’m enjoying all of them from a few yards away.

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