Paired Pelts

Day 25: Lichens can be very selective as to their preferred habitat, but at this particular location, the dominant genus is Peltigera. But which species? That's been puzzling me for some time as I viewed them in a less-than-optimal state of dryness. I had thought the grey, crisp mass might hold both young and old specimens of a single species since there were subtle differences, but I was surprised when, after a good soak in our abundant October rains, two Pelts made themselves apparent. Peltigera britannica (left) is characterized by its bright green colour and dark cephalodia which are easily scraped off the surface of its lobes (a feature which distinguishes it from P. apthosa), and Peltigera membranacea (right) by its thin tissue and rope-like rhizines. These two colonies seem to be campaigning for dominance of the rock face on which they are growing. It's much more to my liking to ponder which will become the next President of Lichenopolis.