#athallia

Athallia pyracea

Flaming firedot lichen

There are a lot of Caloplaca type lichens--crustose lichens with yellow-orange-red apothecia. They used to all be grouped together in the same genus because they look very, very similar. But genetic testing has revealed a lot of cryptic diversity, and lichenologists have divided them up into more correct genera (with still lots and lots of work needed to untangle this messy-ass phylogeny). Now creating new names all well and good for scientific naming convention, but trying to differentiate species with very few defining characteristics with common names is a biiit trickier, hence names like "flaming firedot lichen." I mean, yeah. OK. Sure.

Athallia cerinella

So-called because the thallus - the larger, connecting part of most lichens - is next to invisible, leaving the fruiting bodies apparently sitting by themselves on the substrate. The surface can be bark, wood, or rock, and in this case an artificial path.

The genus was erected in 2012 by Ulf Arup, Patrik Frödén and Ulrik Søchting, who were breaking up the genus Caloplaca into a taxonomy that actually reflects their genetics. All of them produce a particular set of orange pigments known as chemosyndrome A.