#lecidea

 Lecidea laboriosa

Industrious disc lichen

I often wonder how some lichens got their specific epithet. I mean some are obviously descriptive of a trait or locality or habit, but what is it about L. laboriosa that makes it seem like it performs a notable amount of labor? So I looked up the original species description published by Johannes Müller Argoviensis in 1874 (Flora, Regensburg 57: 187 (1874)), and of course it's written in Latin as was the standard of the time. Even with my extremely limited botanical Latin knowledge, I can't see any reason given for the chosen epithet, so I did my due-diligence, and now I can simply guess! I think it got its name from its endolithic thallus embedded in the surface of its siliceous rock substrate. To me, that suggests a certain amount of effort, as shoving hyphae and photobiont cells in-between rock grains has to be labor-intensive, slow-going. But is it less intense to use environmental material to shade and protect your photobiont cells, or to build a multi-level, light filtering thallus yourself like other Lecidea species? Hmmm, a question for the ages. Either way, immersing that thallus in its substrate works for our pal L. laboriosa here, and I am happy to give him the credit for a job well done.

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Lecidea perlatolica

Lecidea sarcogynoides

Lecidea phaeops

Lecidea nylanderi

Nylander's tile lichen

This lichen has a crustose thallus made up of scattered and inconspicuous blue-gray areoles and bluish-gray leprose soredia topping a blue-black prothallus. It has reddish-brown to dark brown apothecia which have a slightly convex to flat disc and a thin, paler margin. It has a chlorococcoid photobiont. L. nylanderi grows on the bark of old conifers in upland, montane habitats.

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Lecidea fuscoatra

When looking at a lichen that looks just like a million other lichens to the naked eye, how are you supposed to tell them apart? Spot testing! Spot testing involves using chemicals dropped onto sections of the thallus and observing any color changing reaction. The three diluted chemical solutions most commonly used contain potassium hydroxide (K-test), calcium hypochlorite/bleach (C-test), and para-phenylenediamine (P-test). You can also do a KC test with a drop of K solution followed by a drop of C. Here’s what L. fuscoatra looks like following C, K, and KC spot tests: 

Pretty distinctive color change, right? Well that C positive reaction, K negative reaction, and KC positive reaction is indicative of the species, and helps to discern it from look-alikes like  Miriquidica deusta and Immersaria athroocarpa which display no reaction to C or K. Pretty neat, huh? 

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