Yellow

With a distinct lack of flowers still, there is one species which is adding a bit of well-needed colour to the countryside.  I refer to the wonderful, yellow lichens which adorn the tree trunks and branches.

This one is - I think - Xanthoria parietina, one of the 'leafy' lichens. Like many other Lichens, they are a symbiotic relationship between a fungus and a green algae which grow together and appear to be one organism.

The yellow colour comes from a pigment in the outer cortex called Parietin. A watery extract from this Lichen has been proven to have antiviral qualities and has been used in laboratory studies, to treat human influenza viruses. It also makes a lovely addition to the otherwise bare branches of the countryside.