Illustration Friday prompt is hitched, and there are few more things in the world more "hitched" than the components of your average lichen.
Lichens are associations between algae (or cyanobacteria as well) and fungi. The blanket term for long-term close association and interaction between two species is symbiosis, and if I remember right it was originally coined specifically to describe how an alga and fungus work together as a lichen. This particular brand of symbiosis used to be taught as the prime example of what's called mutualism, where both organisms benefit from the association and sometimes can't even exist without it. If I was going to call a lichen a mutualistic association I'd explain it by saying that without the alga the fungus wouldn't survive because it can't make its own food, and without the fungus the alga wouldn't survive because it would desiccate.
You'll notice that I said if I was going to call this mutualistic. Thoughts on that changed a number of years ago in the scientific community. Now some scientists prefer to call it commensalism, where one partner benefits and the other isn't harmed. Sort of a marriage of indifference, I guess. Some scientists have even gone so far as to call the association a form of parasitism by the fungus, although I think that's a bit extreme.
Me? I just figure that the two organisms are pretty permanently hitched.
What you're seeing in today's scribble is a loose (very... see below) interpretation of some SEM views of lichens that I found on the web. The green blobs would be algae, and the brown... things are the fungal hyphae surrounding them. And the reason why it's so scribbly when I usually like working on details?
Scribbles for the near future then, I guess. Probably good for me, in the end. It doesn't hurt to loosen up a bit now and then, even if it's not something you're exactly choosing.