Gwinear is a treasure trove!
This is my first foray into trying to identify lichens.
In the photo above is a smooth green lichen covering the stonework around the Indian-head Mason's Mark on the 15th century tower of Gwinear Parish Church.
I look at the orange crustose lichens below every day. This slate upstairs-window ledge is part of a sixteen year old extension to our stone cottage, just a mile from Churchtown.
The lichen below is Xanthoria parietina, the large patch is six cm. long and 4cm. wide. My vocabulary is increasing every minute, thanks to a text book by Frank Dobson.
The Body or Thallus of this lichen, as you can see, is not differentiated into stem, leaves and roots. It does not grow from one point, but appears to gradually cover and hold to a hard surface. Parietin is a bright orange pigment which protects the algal cells from too much sunlight. Lichens require sunshine, rain ( plenty of both in Cornwall), and unpolluted air. The lobes at the outer edge on the Xanthoria are foliate (leaf-like) and some are rising just a little from the slate at the edge of the Thallus. The little raised cup shaped discs with lobed edges in the central area of the Thallus are the apothecia, or fruiting bodies.