Fungi Outer Hebrides

Family: Lecideaceae

Porpidia macrocarpa (DC.) Hertel & A. J. Schwab

Type: Crustose

An extremely variable species. Thallus may be immersed to thin and continuous, or occasionally thicker and areolate. Usually pale greenish-grey but reddish when oxidised. Prothallus is indistinct when thallus immersed, but black and visible when superficial. Large black apothecia (to 3 mm), shiny or matt with persistent margins.Frequent in upland areas of the British Isles, on siliceous rocks and large boulders

Smith, C.W. et al. editors (2009) The Lichens of Great Britain and Irelandd
Dobson, F.S. (2018) Lichens: an Illustrated Guide to the British and Irish Species