Another Rhizocarpon ?

Another Rhizocarpon ?

Observation - Another Rhizocarpon ? - UK and Ireland. Description: Last week I put up photos of Rhizocarpon geographicum from here. Yesterday I noticed small patches o

Last week I put up photos of Rhizocarpon geographicum from here. Yesterday I noticed small patches of R. geographicum surrounded by similar but grey-brown. First thought was this is R. geographicum that has died. But I see in Dobson's Lichen id guide, R. reductum is shown alongside geographicum. So are these pictures showing R. reductum?