Dye found in lichen naturally (5)
I believe the answer is:
henna
'dye' is the definition.
(henna is a kind of dye)
'in lichen naturally' is the wordplay.
'in' indicates the answer is hidden within the clue.
'HENNA' is hidden in the letters of 'lichen naturally'.
'found' acts as a link.
(Other definitions for henna that I've seen before include "(Shrub producing) reddish dyestuff" , "Red hair dye" , "Beauty aid" , "Local colour" , "Pigment used on skin" .)