Notes: on mossy doug-fir log with Peltigera species, including P. britannica

We’ve been looking for the cyanomorph of this species for ages, this is a real treat. Notice that the cyanomorph is not just a formless gray blob — it has reticulate maculae and isidium-like protuberances around the margins, suggesting that, rare though it may be in recent evolutionary times, it descends from a lichen in its own right with complex thallus structure. And a structure rather unlike that of the much larger-lobed, smooth, even-colored chloromorph. (The undersides are very similar, though — not shown in these photos.)