Porpidia macrocarpa f. nigrocruenta?

One for Alan please…

This looks like Porpidia macrocarpa f. nigrocruenta with large apothecia and K+ red in the exciple section.

Taken yesterday on the Cumbria Lichen and Bryophyte Group trip to Scordale on the edge of the Pennines, which has lots of lead mine spoil but this specimen may not have been in this area.

The thallus is thickish and areolate which seems OK for P macrocarpa s. lat. but not s. str. in LGBI though I haven’t seen a full description of s. str..

The thallus medulla is I-, K- and P-.

There are small apothecia with thick margins up to 0.2mm, The biggest apothecia are around 4mm across with contorted margins of the same size.

The spores are in the range 19-24 x 10um, simple usually with a large oil bubble.

The exciple has a dark outside edge and more hyaline brown in its medulla and inner edge.

The hyaline brown area goes red in K.

I think the exciple does not have thinner/filamentous hyphae, though I always find these hard to see.

Would you agree? Chris