Lobaria and Peltigera?

[INHT]

Hi all,

Someone sent me these two photos and I'm pretty sure the first one is lobaria pulmonaria, but not sure about the second. Is it the same thing or a peltigera? Thanks for any help,

Becky

[AlanS]

Hi Becky,

both are Lobaria.

As you say, the first one is Lobaria pulmonaria.

The second is Lobaria scrobiculata. Usually it is more of a brown-grey colour, but when very damp it goes slate-blue, as in the photograph. The network of sharp ridges over the surface is, however, pretty much diagnostic (of this and L. pulmonaria).

In Lobaria pulmonaria, the algal partner is a green alga (Chlorophyta), and so the lichen remains green when wet.
In L. scrobiculata, the "algal" partner is a blue-green alga (Cyanobacteria), and the blue pigment shows through when the lichen is wet.

Alan