I found this on two trees in my yard. I’m wondering if it’s bad and, if so, how bad? It seems to be only on branches that appear dead. Thanks for your help!
That is a fungus, not a lichen, and it looks like Turkey Tail or a similar species. Do not assume it’s edible (just in case you were thinking about it).
As you noted, it’s a sign that the limb is dying or already dead. Fungi like this appear when the tree ages or can’t fully support itself. If the limb were to fall, it could damage your roof, car, or other valuable property, so you might want to remove those limbs preemptively (they might even come down easily by hand). Biologically, this is a slow process and may not be an immediate issue. (I’m a microbiologist who has worked in forest pathology).
If it’s not a threat to your property or safety, you can let it be. The fungus is accelerating the decomposition of the tree, which benefits the habitat in the long run. It’s the circle of life.
The branches do fall down a lot. I have a ton of older crab apple trees on my property, and you’re right—they sometimes break right off.
It can be dangerous if it’s near where you park your cars or where kids play. Especially boys, who tend to be rough with trees.
Potentially capable of spreading?
Haha, well, that’s exactly what’s happening! Those conchs are the fruiting bodies, and at some point (if it hasn’t happened already), they’ll release spores to find a new old tree to infest. But hey, that’s just nature doing its thing!
I think those look more like turkey tails than lichens. They’re feeding on the dead parts of the tree, not causing it to die. These fungi typically appear after the tree is already dead.
The picture isn’t detailed enough, but it appears to be a bracket fungus that lives on wood and acts as a decomposer. Unfortunately, the tree will eventually die. Look up “turkey tail” or “chicken of the woods”—both are edible, but make sure to identify them correctly.
Make sure that branch isn’t hanging over anything important! Mushrooms grow on dead or dying wood, so it will eventually fall off.