Distinguishing Punctelia subrudecta and Parmela sulcata

Hello

I am having difficulty telling the difference between Punctelia subrudecta and Parmelia sulcata.

I am going to ask some experts to help me.

It is OK if the Parmelia sulcata ridges are young and do not yet have soralia.

and if the Punctelia is young and the spots are still very small.

However when the soralia get large, they all look the same to me.

Or maybe it is possible that the two lichens often  grow together so there is one lobe of one next to a lobe of the other species.

1. Please can you tell me any other way I an tell the difference if the spots look as if they could be either lichen?

2. Please can you go through the pictures below and say which ones are identified incorrectly and if so why.  (With a couple of Punctelia jeckeri thrown in)

This first picture is taken from The lichens of Ireland website from the Parmelia sulcata page

 http://www.habitas.org.uk/lichenireland/photo.asp?item=Parmelia-sulcata-mjs

1.  According to Lichen Ireland - Parmelia sulcata

 http://www.habitas.org.uk/lichenireland/photo.asp?item=Parmelia-sulcata-mjs

If I had found the above, I would have called it Punctelia subrudecta

I will now divide up my pictures into what I think is correct:

2. Don't know:  left and lower centre left

3. Parmelia sulcata - St Chads

4. Punctelia-jeckeri?

Punctelia jeckeri - Top of the Mains, Settle

punctelia-subrudecta-arthonia-radiata-rowan-keasden-head-shooting-lodge

punctelia-subrudecta-wood-abovehofman-stainforth-path-lichens

Punctelia subrudecta - Apple tree at The Benns house, Settle

Bottom left  Punctelia subrudecta - top right Parmelia sulcata

usnea-subfloridana-parmelia-sulcata-melanahelia-glabratula-hawthorn-stainforth