Chile cultivated new plant (6)
I believe the answer is:
Here is my best explanation:
'plant' is the definition.
(lichen is a kind of plant)
'chile cultivated new' is the wordplay.
'cultivated' indicates an anagram.
'new' becomes 'n'.
'chile' anagrammed gives 'liche'.
(Other definitions for lichen that I've seen before include "Simple plant often found growing on rocks", "It's found on rocks and tree-trunks", "Crusty, tufty growth on trees and stones", "Symbiotic organism growing on a tree trunk or rock", "Plants found on tree trunks etc", "It grows on rocks or bare ground", "Compound plant not unlike to moss in appearance", "It grows on rocks and trees", "Primitive plants found on rocks" and "Plant growing on stone".)