OK, I put this someplace else in this increasingly-complicated thread, but I have to recommend Startide Rising (and others in its series) by David Brin. (I am also a linguist)

Though thinking about it, I might make a case for tree pheromones being a language if they release different pheromones depending on what is attacking them.

I’d probably just say ‘communication’. Terminology is going to depend on context. All language is communication, but the first poster who responded to zuludeady saying that all communication is language...well I think that’s just silly. Some trees, when attacked by caterpillars, will exude a pheromone that causes…

I’m a speech-language pathologist with both pencil-and-paper ling (like you) and applied ling backgrounds. I explain these distinctions all the time to the families of clients and boy oh boy do people have trouble wrapping their heads around the idea. I do think many posters missed the point you were making, even if…

You might check out the Conlangery podcast.

Vernor Vinge’s Zones of Thought books have some interesting stuff about language impairments. The Tines, a kind of pack-like sentient species, are only intelligent collectively, and may develop different kinds of aphasias when a member dies. David Brin’s Uplift series considers language quite a bit too.