Holly with red bark?

Red-blotched Holly

On a recent trip to Nags Head, we took a walk along the Sweet Gum Trail at Nags Head Woods Preserve, a Nature Conservancy property on the North Carolina Outer Banks. It was a jewel of a find on that overcrowded barrier island, which always leaves this environmentalist a little sick in the stomach and depressed. Too many beach houses and tourists crowded on a narrow sand dune. Too much water use and waste. But that's a discussion I've had with myself too many times. Back to the trail.

Lichens thrive in harsh environments

We found the maritime forest to be just as advertised, quite biologically diverse. I was particularly intrigued by the holly tree with red-blotched bark. What was that tree? It looked like your typical  Ilex opaca (American holly), but could it be something else? The red stuff was on holly trees everywhere, making the mixed forest look somewhat eerie, as if the forest home of the Sir Walter Raleigh's claim were harboring natives in war paint, quietly waiting for the moment to turn the tables on modern invaders who came in SUVs. 

I asked my naturalist friends about the unusual trees at today's bird walk, but no one knew of a holly with red blotches on its bark. Finally, I made it home to do a little Googling. Seems that this wonderful red rash is a growth of that ethereal composite life form called lichen, which is mostly fungus and requires a cooperative arrangement with algae and cyanobacteria in order to survive.

Lichenization is a survival strategy for fungus and it is often found in harsh environments, like the sandy Outer Banks with soil low in nutrition.  Most lichens are gray or green, but the red color of this variety is due to light exposure and dry climate. For more about lichens, check out the book Lichens of North America.