Speculation is fun, as long as long as the speculator is up front about their BS.   Today I’m going waaayyyyyy out on a limb (or up a trunk), so don’t quote anything today as fact.

Walking in Cypress Creek today, I found myself gazing at the big lichen patches “whitewashing” the smooth trunks of laurel oaks. 

Laurel Oak white-“painted” with lichens, by John Bradford

Maybe it was just that 91 degree sun-stroke broiling my noodle, but it looked like the abundant vines along the way tended to sidestep the big white lichen patches.  Among the many vines thereabouts, the ones mostly climbing the oak trunks were  Virginia Creeper.   Virginia Creepers rise with little grabbers (tendrils) that glue themselves to the host’s bark like treefrog toes sticking to your wall.

VA Creeper by John Bradford.

Maybe the lichen is toxic to hug.  Maybe the little tendril feet just don’t cling enthusiastically to a living fungal-algal mass, or maybe the lichen changes enough over time to loosen clingy feet. Or, flip flopped, perhaps the VA creeper kills the lichen under it. Or maybe I’m wrong about the whole thing, maybe got an idea then cherry-picked pictures that agree, but to me the photos below point to vine-lichen discord.  The tender creeper toes don’t seem to like to tread on the lichen. You decide. Discouraging vines probably benefits the host oak.

A pine with a vine

But just three feet from that pine here is an oak, below, crusted with lichens but no climbers.

The vine on the oak above is off to the right side of the lichen patch to its left. (The growing vine can’t see the lichen…so does it look like it “bumps into” lichen and then swerves? The little vine feet seem to tuck their toes into lichen-free nooks.)

Vine above rising through a lichen gap on an oak. (Did water running down the gap favor the vine and disfavor the lichen?)

Two dark colored vines climbing vertically on the right away from the big white patch on an oak. (The green diagonal stem across the patch is not attached to the tree.)