Growing on the trunk of a small Western Hemlock, in Hemlock dominated forest. Scattered all over the ground in the surrounding area.
I'd heard there were cool lichens up on San Bruno, so I was pleasantly unsurprised to find a new-to-me lichen up there. This definitely doesn't have the hairy lobe tips of L. hallii, so I feel pretty good about the ID. There is one record of this species from Marin, but it seems like it might be unusual around the Bay.
With fruiting bodies, and on tree trunk
On ground (I took picture of it against bark).
mixed beech forest on red beech; 4th picture is underside
Large leave lichen with loose attachments, upper surface pale bluish green, strongly ridged, indented between ridges. lower surface brownish
found on trees in humid forests, This sample was found attached to a fallen stick
Lobaria is a genus of lichens commonly known as "lungwort" or "lung moss" as their physical shape somewhat resembles a lung. Lobaria species are unusual in that they have a three-part symbiosis, containing a fungus, an alga and a cyanobacterium, the presence of the cyanobacterium allowing nitrogen fixation.