Sunday, May 5, 2013

The Fine Art of Botanical Self-Defense: Spines

So you think spring is the time of soft, green grass; brightly, colored flowers; and sweet smells. And it is. But don't be fooled. That innocent-looking garden is armed and (somewhat) dangerous. Welcome to the world of thorns, spines, and prickles.

First, a quickie lesson and/or review.
Roses don't have thorns--though many poets would have it so.
Roses have prickles.  They can--with the right gloves--be scraped off.  Thorns and spines, not so much.

The sharp plant bits that snag our clothes, puncture our gloveless fingers, and surprise unwanted guests are defined by their tissues rather than the pain they produce.

Thorns are modified branches: think hawthorne trees and flowering quince
Spines are modified leaves: think cacti and holly
Prickles are modified bark or skin (sort of), basically epidermal tissue: think roses

The spines in my garden come in two varieties:  ones that appear at the leaf margins and ones erupting from the branches.

Some California Lilacs (Ceanothus spp.) have small holly-like leaves.  And for most of the year, they're really all you see.  But when the flowers begin to bloom, I often lose sight of the rest of the plant, and want to lean in for a better look

Ceanothus gloriosus ' Pt. Reyes'

But they are so small and the flowers are so very small, that you're practically nose-to-nose with them before you realize how close you're coming to some less than friendly spines.

Barberry (Berberis spp.) was one of the first new plants I encountered when we moved up here. I loved the textures and the colors; it seemed both fierce and graceful and now I have four of them.

The darwinii has these amazingly orange flowers, and, like the Ceanothus above, it has small, spiny leaves.

Berberis darwinii 
Berberis thunbergii 'Rosy Glow'

On the other hand, the lovely 'Rosy Glow' has smooth, soft leaves. But the spines hide underneath them. 

These spines do more than frustrate the tactile gardener; they protect the plant from actual predators. Neither large animals nor small insects (with relatively large mouths) like munching or even walking through "armed" (truly, the technical term) plants.  Which is probably why these particular shrubs make charming hedges for those whose neighbors are less than congenial.


  1. Ah, the joy of spines and spikes, we have Berberis Rosy Glow as well, a beautiful foliage plant.

    1. Isn't it! When I bought mine, the salesperson warned me that it gets really big and spreads. Perfect!

  2. The background information is great...really loved the photos. Thank you for sharing.

    1. Thank you Charlie! I really appreciate it. Very interesting site you have.

  3. When it comes to spines, I give stinging nettle the gold medal. Just brush this plant with some bare skin and you are in real pain. Also a host plant for red admiral butterflies.

  4. Oh yes, Jason! We have tons of them growing at the edge of the forest behind us and they pop up in our vegetable garden. But I didn't know they were a butterfly host. So when someone points out that I missed digging out a big section of nettles, I'll just say it's for the butterflies. And it will be mostly true. Thanks!

  5. I could use a few of those spiky ones underneath the fir trees...the dogs in the neighborhood love to come by and eat the suet on the ground...and the first thing they do after is a leave a calling card.

    Love the shots you got..and you have made even the ubiquitous barberry look beautiful.


    1. Thanks Jen! Mine are doing a great job of protecting ONE side of my dogwood. And doesn't Boo scare those dogs away? She's falling down on her job.

  6. Hello Emily, thanks for the lesson, I can now say that some of the roses I have seem to be armed with "prickles on prickles" and be correct! Shame it doesn't make the pain any less when I accidentally get caught on one. That berberis is a gorgeous yellow-orange in that photo, it almost glows.