Vegetation initially found living on restricted area (5)
I believe the answer is:
flora
'vegetation' is the definition.
(I know that vegetation can be written as flora)
'initially found living on restricted area' is the wordplay.
'initially' suggests taking the first letters.
'area' becomes 'a' (maths abbreviation).
The first letters of 'found living on restricted' is 'flor'.
'flor'+'a'='FLORA'
(Other definitions for flora that I've seen before include "Plant life of a given place" , "growing flowers" , "For example, Miss Macdonald" , "Lots of plants" , "Plants < girl" .)