Emerald lichen on tree in dense forest near Bergen, North Holland
A couple of months after I had made (and published) this photo I discovered a painting by Narcisse Virgilio Díaz de la Peña (1807 – 1876), a French painter of the Barbizon school, which looks very similar even though being some 150 years older:
Narcisse Virgilio Díaz de la Peña, Forest of Fontainebleau, 1868, Dallas Museum of Art
Stan