#while not technically correct it's the framework by which we (people in western science) categorize and recognize them

[treddnevers]

Hey I’m the op from the lichen poll thingy, I really love all the wonderful tags everyone is putting in there and so curious to learn more. Didn’t know a lot about lichen before this, can only ID like 3 of them (wanted to write species but that’s not correct I assume?), so would you care to elaborate what you mean by your tags? Would love to learn!

HELL YES. I hope ur cool w/ me posting this publicly, I take any opportunity I can to gush about lichens. For reference, my tags on that poll were something along the lines of: "do YOU challenge the foundational concept of a species in western science with your existence? well you actually do but not as directly as a lichen." I'm not going to properly cite myself here because I'm lazy so take some things with a grain of salt, but BASICALLY:

- a lichen is a symbiotic relationship between a fungi (typically an ascomycete, though there are a few basidiomycete lichens) and a photosynthetic organism (usually green algae, sometimes cyanobacteria)

- the way we classify lichens, taxonomically, is based on their fungal part, also called a mycobiont. so the species name of a lichen - let's take my fruticose friend Usnea longissima for example - refers only to that fungal part.

- getting a positive species ID on that photosynthetic partner, also called a photobiont, is a lot harder, but we know that there's some overlap between the species of photobionts that different lichen employ

- so why don't we just refer to a lichen based on the mycobiont exclusively?

- because without the photobiont, the mycobiont will not grow into a lichen in any recognizable way. a lichen is NOT a lichen if it is just the fungi species it is named for, and it is not a lichen if it is just free-living algae.

- isn't it cool that some forms of life literally cannot exist as individuals? their existence is predicated on the fact that they are in partnership, inextricably linked from what our conventions of species differentiation would consider an entirely different organism. except, wait: so are we.

- human beings literally cannot function without the bacteria, fungi, and countless other microorganisms living in our intestines, on the surface of our skin, and just about everywhere else. i believe current literature states that >50% of the cells comprising the average human body are nonhuman. your microbiome is the reason you aren't just a tube that constantly leaks out partially-dissolved food matter!

- so who's to say that humans even exist as a distinct species? from a certain perspective, a human being is just an organic scaffold that houses a community of billions of individuals.

- get out there and appreciate your local lichens!!!