Unguiculariopsis lesdainii but ?host

[JennyS]

I think this is Unguiculariopsis lesdainii on a fence post Lecanora - but I'm struggling with the host identity!
Unguiculariopsis apothecia with swollen-based, whitish hairs, becoming +/- open as mature and not bleeding K+ red. Spores 5-6(-7) x 2 µm.

Host Lecanora C-,K-, P-,UV-, no crystals and no granules in the epithecium in water or K, but yellow (?)granules in margins in water under polarised light.
It looks much more like Myriolecis dispersa (Lecanora dispersa) than Lecanora saligna but the lack of granules in the epithecium and presence of yellow granules in margins has thrown me!

[Neil Sanderson]

Jenny

I have not found Unguiculariopsis lesdainii, but I did check someone esle's specimen from a fence post in Hampshire and this was similar. The host was definitely not Lecanora saligna and like yours appeared to be Myriolecis dispersa.

Neil

[JennyS]

Thanks Neil - the lack of granules in the epithecium, but their presence in the margins confused me!

However checking the Italic 8 descriptium for M. dispersa it includes:

Thalline exciple corticate, obscured by granules insoluble in K

though that's not mentioned in the LGBI3 account