Cladonias All The Way Down

Day 22: The signature phrase, "It's turtles all the way down" has been attributed to a number of different sources (Bertrand Russell or William James among others) and was popularized by none other than Stephen Hawking in more recent times. It refers to a bit of mythology (again ascribed to various cultures) in which the Earth is described as resting on the back of a huge turtle. The expression results from a confrontation between a cosmologist following his explanation of the nature of the Universe and a member of the audience who puts forth the legend as an alternate theory. When asked what supports the first turtle, the challenger asserts, "Another turtle." The cosmologist then responds, "But what does that turtle stand on?" The reply follows the legend exactly, "Another turtle, of course. It's turtles all the way down."

In the fascinating world of lichens, nothing proves the myth more visibly than the Cladonias. On close examination, it's not hard to find proof that it's Cladonias all the way down. (Cladonia grayi)

Cladonia Grayi

Day 159: In my numerous walks on the Westside Road, I've noticed a paucity of lichen diversity and lichens in general. However, a few days ago, I came across a most luxurious colony of Cladonia grayi, one of the "mealy" pixie-cup species. It is not an uncommon lichen, but here was confined to one shelf of a rock outcropping about 8 inches wide and 18 inches long. Its occurrence in such a limited area made me wonder what conditions allowed it to establish there and not elsewhere on the same exposure. Is it some subtle difference in the substrate, a vein of some mineral in the rock? It was certainly nothing I could detect with the naked eye. Oh, for access to a laboratory and a tame lichen expert! There is so much I'd like to know about these fascinating life forms.