Leaves off sides and tops of small trees are variegated (7)
I believe the answer is:
desists
'leaves off' is the definition.
(I've seen this in another clue)
'sides and tops of small trees are variegated' is the wordplay.
'and' means one lot of letters go next to another.
'tops of' indicates taking the first letters.
'are variegated' indicates anagramming the letters.
The first letters of 'small trees' is 'st'.
'sides' put after 'st' is 'stsides'.
'stsides' anagrammed gives 'DESISTS'.
(Other definitions for desists that I've seen before include "Ceases" , "Stops, refrains from" .)