Lichen makes for interesting abstracts, usually in circular patterns of orange, yellow, green, white, black or grey.
Orange and white circular patterns on a cemetery wall in France.
Grey, green and yellow lichen texture a wall in Bruge, Belgium.
A nearby stone wall has the same colours of lichen.
Circular lichen abstract on a ceiling in Mesa Verde National Park, Colorado.
Tiny orange, white and black lichen patterns on a stone beach on Inisheer Island in Ireland.
Very large lichen patterns on a stone wall of the Cong Abbey in Ireland.
On this Vancouver tree the lichen has spread to create a solid patch of yellow-green.
More on the Daily Post’s Weekly Photo Challenge: Abstract.
Batz Gallery 
Great captures! 🙂
Just gorgeous.