Placopsis lambii

So like, generally I agree that it’s not polite to stare. But like, P. lambii has A LOT going on, and it takes a good minute to take it all in. Like you might look at it and wonder, why does it have a weird thing that looks like a butthole? What are those gray spots? Or green spots? Or pink spots? Why is it sometimes really round and sometimes really blobby? All great questions, all of which I will do my best to answer. This crustose lichen has a radiating, placodioid thallus (rosette shaped, tile-like toward the center, lobe-like toward the outside). It is grey, cream, or tan, often with a pink or green tinge. The gray or green cracks or pustules you can see are soralia, which produce vegetative propagules in the form of soredia. The weird butthole-shaped, brownish-pinkish blob near the thallus center is a large cephalodia--a section of the thallus containing a secondary, cyanobacterial photobiont in an otherwise algal lichen. P. lambii doesn’t always have cephalodia--they are often only found in specimens that live in particularly moist environments. It also only occasionally produces apothecia, which have a yellow or bubble-gum pink disc and a prominent margin. P. lambii grows on siliceous rock in cold, damp areas near water. It has a scattered and rare distribution in Europe, Africa, South America, Asia, and New Zealand. This fella is easily confused with P. gelida, but they are genetically and chemically distinct. Both can be incredibly variable, so good luck IDing them in the field! At least you will know you are looking at a Placopsis, right? Because no other lichen is quite this same level of odd. 

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Placopsis gelida 

Bull’s-eye lichen

I told my partner that I thought this lichen looked like a boob and he gave me a weird look. Just thought I’d share. Anyway, this is P. gelida! It’s a crustose lichen that forms fissured, placodioid rosettes. It can also appear more areolate depending on the growth stage it is in. It is typically pale beige in color with conspicuous darker peach to brown cephalodia and greenish-gray soredia spotted over the surface, often concetrated toward the center of the rosette. Apothecia are rare, and form immersed, pruinose discs. It grows on rocks and pebbles in alpine-arctic habitats. Probably. Take everything said above with a probably. Apparently P. gelida is really hard to distinguish from P. lambii, and so a lot of sources of information are unreliable, and more research is needed to delimitate the exact range, growth habits, and variations of each. They may even need to be synonomized. Both are good and pure and yeah, kinda look like boobs if you squint your eyes and use your imagination. Don’t judge me. 

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