Two very common and easily identifiable lichens found all over Petersfield

 The large 'apple-green' (slightly yellowish-green) patches you see on trees, especially on the Heath are Flavoparmelia caperata, one of our commonest and fastest growing lichens -the patches may only be decades old.

Sometimes you see fruiting bodies 'apothecia', you can also see granular soredia towards the centre of the patch, these are bits of the lichen that can blow away to start another one.

The second lichen is Parmotrema perlatum, this forms the more bluey green similar sized patches often found on the same tree.

This one is less flat on the tree trunk and often has fluffy soredia along the edges of the lobes. Another give away are whiskers along the edges of the lobes.

Nothing is simple in the lichen world and there is another species of Flavoparmelia on the Heath, it looks much the same but is all round smaller with fluffy rather than granular soredia. This is Flavoparmelia soredians. The chemistry is also different, a spot of alkali turns it red whereas its larger relative doesn't react.