I too have encountered lichens on the hills of Glen Affric. The photograph above shows Ophioparma ventosa, a lichen that I found there about 20 years ago. A synonym of this species is Haematomma ventosum, where the generic part of the name alludes to the blood-red pigment that can be seen in spots on the surface of the crustose lichen. My involvement with the lichen concerned the chemical structure of this pigment, which had been isolated and given the name haemoventosin.
A colleague in Germany who was an expert in lichen chemistry doubted the chemical structure that had been proposed and provided us with material to investigate. Quite quickly we were able to demonstrate spectroscopically that the published structure could not be correct, but it was 10 years before I came up with a chemical transformation that established the final details of the revised structure (a napthoquinone derivative).
Another naphthoquinone derivative (rhodocladonic acid) is the characteristic red pigment of numerous Cladonia lichen species. However in the case of Stuart MacRae’s lichen, Cladonia belllidiflora, a brown-red crystalline compound called bellidiflorin was reported in 1907 and shown to be a complex anthraquinone derivative in papers published in 1975 and 1990. The picture below shows a species somewhat similar to Cladonia bellidiflora. It is Cladonia cristatella from North America, where it is commonly known as the British soldier lichen.
Postscript. We published the haemoventosin structure in 1995. Two years later the Chemistry Department of the University of Glasgow celebrated the 250th anniversary of the establishment in 1747 of the first lectureship in chemistry at the University. Charged with finding some appropriate music, I searched for music associated with the date 1747 and discovered Oswald’s ‘Airs for the Spring [and Summer, Autumn, Winter]’ in the University’s Euing Collection. It appears the association with the date 1747 arose because the library catalogue entry states “Licence, dated 23-10-1747, wanting”. The British Library catalogue gives the date of publication as 1755.