thallus
aged
algae
background
bark
biology
birch
branch
bright
brown
close up
closeup
color
cyanobacteria
detail
environment
foliose
forest
fungi
fungus
golden
green
grow
growth
lichen
lichens
macro
natural
nature
old
orange
organism
outdoor
pattern
plant
rough
surface
symbiosis
texture
tree
trunk
winter
wood
yellow