Orange Snot on Juniper

Trees are so easy to enjoy. You don’t have to even know what tree species you’re looking at in order to see strange and compelling things. The best ways to learn about trees is to deliberately and studiously look at them. It takes practice to become fluent in trees.

I was sent some photos from a random email inquiring about “orange snot” on their “pine”. Awesome. Here are some photos from my collection of what this person is looking at:

Not a pine species, a juniper species, Juniperus virginiana. Commonly called Eastern Red Cedar, or Juniper.

And not snot, but definitely feels like it. That strange orange snot-ball is the “telial horn” of a cedar-rust fungus, and is something very unique even within the fungal kingdom. Only a very few kinds of fungi produce these weird gooey horns.

These are highly visible after early spring rain showers on Junipers. You just have to be looking.

Here’s what they look like at a glance, not zoomed in:

I won’t bore you with the details; cedar-rusts have a complex relationship with some trees in the rosaceae, the rose family. Some examples of those trees in the rose family are apples, crabapples, hawthorns, and quince.

The same fungus can infect the leaves and fruits of the aforementioned trees. This type of infection occurs every year, and is especially prevalent in years when the new leaves are emerging at the same time as these orange snot-balls.

And that’s exactly what happened this year! We’re coming off of a six-day rain streak.

Interestingly, while the infection takes place in early/mid spring, the symptoms don’t appear on the trees until mid/late summer. Those symptoms are lesions on the leaves, which can expand to the point of leaf-death, and early leaf droppage. It can also cause weird growths on the leaves and fruit, like this:

The same organisms that grows those orange snot-balls are the same organisms causing this symptom on a totally unrelated plant.

This kind of thing is traditionally looked at as a “disease”, and sure, it is technically a fungal infection. Another way to appreciate this is to see it as an fascinating example of what you can find by just looking at trees.

This is a good place to say that if you find something curious on trees, take some photos. Send them to me, let’s talk about it.

Okay, talk to ya later,

Tree First